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Glossary

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A

Acidic, Acids

Like an acid. In chemistry, acids are molecules that have a pH below 7. Acids can donate hydrogen ions to other molecules in chemical reactions.

Acidemia

Acid in the blood. Acidemia is caused when processes in the body are not working as they should, causing acids to build up in the blood and tissues. Acids in the blood can cause damage to the body if the condition causing acidemia is not treated.

Aciduria

Acid in the urine. Aciduria is caused when processes in the body are not working as they should, causing acids to build up in the body and come out in the urine. Acids can damage the body if the condition causing aciduria is not treated.

Acute

Severe or intense. An acute type of a condition usually has more symptoms or more intense symptoms than other forms of that condition. An acute symptom may come on quickly or need urgent care.

Acute fatty liver of pregnancy (AFLP)

A rare but serious condition in the mother that can occur late in pregnancy. Fat builds up in the mother’s liver and damages it. The most common sign of AFLP is yellow skin and/or eyes (jaundice). Sometimes, a mother’s AFLP is caused because their unborn baby has a condition that releases toxins inside the mother. If your baby’s mother had AFLP, your baby should be screened for certain newborn conditions.

Acylcarnitines

A substance that helps your body break down fats for energy. Acylcarnitines help move fat into the mitochondria (a structure inside the cell) to be broken down. In Blood Spot Screening, finding too high or too low levels of certain acylcarnitines in your baby’s blood may mean they need further testing.

Adrenal crisis

A life-threatening condition that happens when there is not enough cortisol in your body. Signs can include altered mental status, abdominal pain, nausea/vomiting, or fever. Adrenal crisis can lead to low blood pressure, seizures, and coma, and should be treated as soon as possible.

Adrenal glands

Small structures on top of your kidneys. Adrenal glands make several important chemical messengers (hormones).

Advisory Committee on Heritable Disorders in Newborns and Children (ACHDNC)

A federal committee made up of doctors, scientists, parents, ethicists, and researchers. This group advises the United States Secretary of Health and Human Services about newborn screening and related topics. Learn more about the ACHDNC.

Advocacy

Support of a cause. Advocacy organizations for newborn screening and for the conditions found by newborn screening help raise awareness, develop governmental policies, and fundraise for their cause.

Airway clearance therapy (ACT)

A physical process to help clear the lungs, such as clapping the back, chest, and sides with a cupped hand or a special tool called a percussor. Older children can also use specific methods of controlled breathing, huffing, and/or coughing. Devices like vests or inhaling tools can also be used. Also called airway clearance technique.

Aldosterone

A chemical messenger (hormone) that maintains normal salt levels in the body.

Allele

Everyone has two sets of genes – one copy inherited from your biological mom and one copy inherited from your biological dad. When these genes have slight differences, they are called alleles. These differences usually do not impact your health, but certain alleles can cause genetic conditions.

Alopecia

Hair loss, or not growing hair in places where hair normally grows.

Amino acid

A class of chemicals that have a similar structure. Proteins are chains made up of amino acids. Cells use 20 amino acids to build proteins. Examples of amino acids used to build proteins are arginine, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, tyrosine, tryptophan, and valine.

Some amino acids, like citrulline and homocysteine, are not part of proteins but have other important jobs in the body.

Amino acid disorder

Condition caused when the body has trouble breaking down certain parts of proteins called amino acids. Several genes make special proteins (called enzymes) that help break down amino acids and get rid of waste. When one of these genes does not make a working enzyme, it can cause an amino acid disorder.

Ammonia

A waste product made by your body from protein digestion. Normally, your body changes ammonia into a less toxic waste product called urea through a process called the urea cycle. Urea is passed through the body in urine. High levels of ammonia (hyperammonemia) in the body are harmful.

Analgesics

Medicines to treat pain. Examples of common analgesics include acetaminophen and ibuprofen.

Anemia

Low level of red blood cells in the blood.

Antibiotics

Medicines that kill bacteria.

Antibody

Proteins that mark foreign substances for destruction by your immune system. Antibodies attach to bad bacteria, viruses, or other substances in your body that may harm you, then immune cells kill anything the antibody is attached to. Also called immunoglobulins (Ig).

Anticoagulant

Medicine that helps prevent blood clots.

Anti-inflammatories

Medicines that reduce swelling. Common anti-inflammatories are steroids (like cortisone or prednisone) and NSAIDs (nonsteroidal anti-inflammatory drugs, like ibuprofen or naproxen).

Antimicrobial

Treatment that kills small organisms that infect the body. Antimicrobial therapies include antibiotics (kill bacteria), antivirals (kill viruses), and antifungals (kill fungi like yeast).

Antioxidant

Substance that protects the body from certain kinds of damage, like the damage caused from reactive oxygen species.

Antiviral

Treatment that kills viruses.

Apgar score

A scoring system for assessing a newborn’s health right after birth. The Apgar score measures five key areas of health: skin color, heart rate, reflexes, muscle tone, and breathing rate. Most healthy babies score 7 or higher. Babies with scores lower than 7 may need medical help. Babies with scores lower than 5 may need special hospital care.

Arginine

An amino acid that your body uses to build proteins.

Argininosuccinic acid

An amino acid that is not used to build proteins. Argininosuccinic acid is needed to build arginine, which is an amino acid used in proteins. Argininosuccinic acid is part of the urea cycle.

Arrhythmia

Irregular heartbeat. Arrhythmias include a fast heart beat (tachycardia), a slow heart beat (bradycardia), or an irregular pattern such as skipping beats.

Ataxia

A loss of balance caused by brain, nerve, or muscle damage.

Atresia

When an opening in the body is not formed correctly.

Atrophy

When parts of the body start to break down, weaken, or get smaller.

Attenuated

Weakened, reduced, or less severe.

Audiologist

A doctor who has extra training and knowledge in hearing differences and balance issues.

Audiology evaluation

A series of hearing tests an audiologist performs to see if your baby is deaf or hard of hearing and if so, to what degree.

Autoimmune

When your immune system mistakenly attacks your healthy cells.

Automated auditory brainstem response (AABR)

A type of hearing screening method used to test an infant’s ability to hear.

Autosomal dominant

One way a condition can run in families (inheritance pattern). Everyone receives two copies of all genes – one copy inherited from the mom and one copy inherited from the dad. If a condition is autosomal dominant, it means your baby can have the condition if only one of those gene copies does not work. In this case, the mom or the dad usually has the condition also.

Autosomal recessive

One way a condition can run in families (inheritance pattern). Everyone receives two copies of all genes – one copy inherited from the mom and one copy inherited from the dad. If a condition is autosomal recessive, it means your baby can have the condition if both of those gene copies do not work. In this case, the mom and the dad usually do not have the condition because only one of each of their gene copies does not work (they are carriers).

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B

B cells

A type of blood cell that is a part of the immune system. B cells are made in our bone marrow and make antibodies.

Betaine

A chemical that occurs naturally in your body and in food. Betaine is used as a treatment for certain conditions with high homocysteine levels. It helps the enzyme that breaks down homocysteine work. Also called betaine anhydrous or trimethylglycine.

BH4 (tetrahydrobiopterin)

A type of biopterin that is naturally present in your body to help certain enzymes work (cofactor). It is also taken as a supplement to treat some conditions found by newborn screening.

Bilateral

Both sides. For example, bilateral hearing loss occurs in both ears.

Bilirubin

A yellowish substance made during your body's normal process of breaking down red blood cells. A healthy liver will remove most of the bilirubin in your body. If your liver is damaged or is not working well, bilirubin levels can get too high (hyperbilirubinemia). When too much bilirubin gets into the blood, it can cause your skin and eyes to turn yellow (jaundice).

Biopterin

A group of substances that help certain enzymes work (cofactors). Tetrahydrobiopterin (BH4) is a type of biopterin.

Biosynthesis

Processes inside your body that build complex substances from simple ones.

Biotin

A vitamin that is needed to help your body break down food and make energy. It is an enzyme cofactor (it helps processes in the body happen). Biotin is so important that your body recycles it so there is always some available.

Birth prevalence

A measure of how often a condition is found in newborns. If the birth prevalence is 1 in 1000, that means that in a group of 1000 newborns, one newborn has the condition.

Bone marrow

The space inside your bones where blood cells are made.

Branched-chain amino acids

A type of amino acid (the building blocks of proteins) with a chemical structure that looks like a branch. The branched amino acids are leucine, isoleucine, and valine.

Bronchodilators

Medicines that widen the airways of the lungs.

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C

Candidiasis

An infection of the body with yeast (a type of fungus). It is commonly called thrush when it happens in the mouth. When it happens in the vagina, it is commonly called a yeast infection. Some diaper rashes are caused by candidiasis on the skin.

Cardiologist

A doctor with extra training in the heart and blood vessels.

Cardiomyopathy

A large, thick, or stiff heart that has trouble pumping blood to the body.

Carnitine

A substance that helps your body break down fats for energy. Pieces of fats are attached to carnitine to form an acylcarnitine. Acylcarnitine helps move the fat into the mitochondria (a structure inside the cell) to be broken down.

In Blood Spot Screening, finding high or low levels of carnitine in your baby’s blood may mean they need further testing.

L-carnitine is a common treatment given to babies with certain conditions to help them digest fats.

Carrier

Everyone has two sets of genes – one copy inherited from your mom and one copy inherited from your dad. Some conditions only occur when both copies of a certain gene do not work (autosomal recessive). For these conditions, people who have one normal gene copy and one gene copy that does not work are called carriers. Carriers do not have the condition, but they can pass it on to their baby. If a carrier has a child with another a carrier, their child has a 1 in 4 chance of getting two gene copies that do not work.

Cataracts

Cloudy spots on the eye.

Channel

A type of protein that allows atoms, like chloride, to go in and out of cells.

Chaperone therapy

Medicine that improves enzyme activity.

Chromosome

Thread-like DNA structures that contain all of your genetic material. You have 46 chromosomes that are in 23 pairs. 22 of the pairs look the same for men and women. The 23rd chromosome pair is called the sex chromosome pair. Typical biological females have two X chromosomes (XX). Typical biological males have one X chromosome and one Y chromosome (XY).

Chronic

Ongoing. A chronic condition can either last a long time or can constantly come and go.

Chloride

An atom that your body uses to control acidity and fluid levels in cells.

Cholestasis

A liver disease. Bile is a fluid that your liver makes to help you digest food. In cholestasis, bile is blocked or reduced. Signs of cholestasis in babies include yellow skin or eyes, dark urine, and light-colored stool.

Citrulline

An amino acid that is not used to build proteins. Citrulline is needed to build arginine, which is an amino acid used in proteins. Citrulline is part of the urea cycle.

Cleft palate

A hole in the top of the mouth (palate) that can sometimes include an opening in the lip (cleft lip). Cleft palate occurs when the top of the mouth does not come together before birth.

Critical congenital heart disease (CCHD)

A group of serious heart conditions present at birth. Children with these conditions usually need surgery or other intervention before 1 year of age. 

Cochlear implants

A device that converts sound into electrical signals and then transfers those signals directly to a nerve that helps the person hear. Cochlear implants are put in during outpatient surgery.

Cofactor

Substances that help enzymes work. Examples of cofactors are biotin, vitamin B-12, and tetrahydrobiopterin (BH4).

Coma

A deep state of prolonged unconsciousness from which a person cannot be awakened.

Community-based organizations (CBOs)

In medical terms, local agencies that provide services, education, and support to families affected by certain conditions.

Congenital

Present at or before birth. Congenital infections happen when the baby is infected with a virus before or during birth.

Contracture

Tightening that can prevent normal movement of a body part.

Cortisol

A chemical messenger (hormone) that keeps blood sugar levels normal and protects the body during stress.

Creatine synthesis disorder

Condition caused when the body has trouble making creatine. Certain genes make proteins (enzymes) that are needed to make creatine. When one of those genes does not work, it can cause a creatine synthesis disorder. Also called creatine deficiency syndrome.

Cued speech

A visual method of speech that uses hand signals to communicate speech sounds. Cued speech is different from American Sign Language, which uses hand signals to communicate words or concepts.

Cyanosis

Blue color to the skin, lips, or fingernails that is usually caused by low oxygen levels.

Cysts

Fluid-filled sacs in or on the body.

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D

Defect

Something in the body has not formed in the typical way.

Deficiency

Lacking, not enough, or low levels.

Dehydration

Not enough fluid in the body. In babies, signs of dehydration include fewer than 6 wet diapers in a day, dry mouth, fewer tears when crying, sunken eyes, greyish skin, or a sunken soft spot.

Developmental regression

Loss of developmental milestones. For example, a baby who was able to walk stops walking.

Diagnose

When a health care provider determines which medical condition your baby has.

Diagnostic test

A test used to confirm or rule out the presence of a medical condition.

Dialysis

A treatment that filters blood.

Dysostosis multiplex

Abnormal bone growth that can change the shape of many bones in the body. Dysostosis multiplex is seen in Mucopolysaccharidosis type I and Mucopolysaccharidosis type II.

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E

Echocardiogram

An ultrasound picture of the heart. An ultrasound creates an image of the inside of your body using sound waves.

Ectopia lentis

When the lens in the eye is in the wrong place.

Eczema

Dry, scaly skin

Electrocardiogram (ECG)

A test that records the electrical activity of the heart.

Endocrine disorder

A condition that produces too much or too little chemical messengers (hormones) in the body.

Endocrinologist

A doctor with extra training in how hormones (chemical messengers) and glands (body structures that make hormones) work in the body.

Enzyme

Proteins that make or speed up chemical changes. Enzymes can build, break down, or change substances in the body. There are over a thousand enzymes inside your cells that help your body with the processes needed for life.

Enzyme replacement therapy

A treatment where an enzyme that the body needs is provided into the blood (intravenously). In conditions where an enzyme is not made correctly by your body, replacing it with a working enzyme can relieve symptoms.

Epilepsy

A condition in the brain that causes sudden changes in the brain’s electricity (seizures).

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F

Failure to thrive

When a baby is not growing enough compared to average babies. Failure to thrive can occur when babies have a condition that does not let them use food for energy as well as they need to.

False-negative result

A result that is in-range, even though the newborn has the condition.

False-positive result

A result that is out-of-range, even though the newborn does not have the condition.

Fasting

Going a long time without food. Babies with certain conditions must eat frequently (avoid fasting) to prevent symptoms.

Fatty acid

A type of fat. Fatty acids can be saturated or unsaturated, and can also be very long chain, long chain, medium chain, or small chain depending on their chemical structure.

Fatty acid oxidation disorder

Condition caused when the body has trouble breaking down fats and turning them into energy. Several genes make proteins (enzymes and transporters) that help break down fats. When one of these genes does not work, a fatty acid oxidation disorder can result.

Fibrosis

When the body creates scar tissue. In conditions with fibrosis, too much scar tissue may be created where it does not belong.

Fluctuating

Changing. Babies with fluctuating hearing loss may get better or worse over time.

Folate

One of the B vitamins, also called folic acid or vitamin B9.

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G

Galactose

A type of sugar that is found in food, including milk and products made from milk. Your body also makes galactose when it breaks apart another sugar found in milk called lactose.

Gene

A message written in the DNA inside every cell that gives the body instructions on how to build a certain protein. Each of our cells has two copies of most genes, one copy from our biological mother and one copy from our biological father. We have thousands of different genes.

Gene therapy

Gene therapy treats genetic conditions caused when certain genes in the body do not work correctly. Gene therapy delivers working copies of the gene to cells in the body. The cells use the working gene copies to make important proteins needed for the body to function. The ability of the body to make these proteins with the new working gene copies helps treat the signs and symptoms of the genetic condition. Gene therapy is available for a few different genetic conditions.

Genetic

Having to do with genes. For example, a genetic condition is caused by a nonworking gene.

Genetic condition

A condition caused by an error in a gene. Errors in genes can be passed down from parent to child (inherited). Errors can also happen in a baby’s genes even when the parents do not have an error in their genes (sporadic).

Genetic counselor

A counselor who has extra training and knowledge in changes to our genes that can affect our health. They also provide support to those with genetic conditions.

Glycine

An amino acid that your body uses to build proteins.

Glycogen

A substance made when your body links many sugars together. Glycogen is how your body stores sugar for later use.

Glycosaminoglycans (GAGs)

Complex sugars that your body breaks down in the lysosomes (special compartments inside your cells that process nutrients).

Glycosphingolipid

A type of fat that is necessary for healthy cells but can be harmful at high levels.

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H

Health care provider

Any person, such as a primary care physician, nurse, or therapist, who provides health care services for you or your baby.

Hematologist

A doctor with extra training on conditions involving the blood or parts of the body that make blood, like the bone marrow and spleen. Hematologists also treat conditions involving the lymphatic system, a system that helps remove waste from the blood.

Hemoglobin (Hgb)

A protein that is responsible for carrying oxygen and carbon dioxide in the blood inside red blood cells. Hemoglobin also contains iron that is responsible for the red color of blood. There are many types of hemoglobin. Fetal hemoglobin, or hemoglobin F, is found in all babies. Hemoglobin S (sickle hemoglobin) and hemoglobin C can cause conditions (called hemoglobinopathies) that affect the blood.

Hemoglobin disorder or hemoglobinopathy

A condition caused by changes to hemoglobin that affect the shape or amount of red blood cells in the body in an unhealthy way.

Hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome

A rare but serious condition in the mother during pregnancy that includes a breakdown of red blood cells (hemolysis), liver damage (elevated liver enzymes), and low clotting cells (platelets) in your blood. This condition may result when the baby has certain health conditions. Babies of mothers who had this condition should be screened for certain newborn conditions.

Hemolytic anemia

A condition caused when red blood cells are destroyed too quickly.

Hepatomegaly

Unusually large liver.

Hernia

Part of the intestine or fatty tissue forms a soft bump under the skin at a weak spot in the body. An umbilical hernia happens near the belly button. An inguinal hernia happens near the groin.

Heterozygote

A person with one working copy and one nonworking copy of a gene. Sometimes called a carrier.

Histidine

An amino acid that your body uses to build proteins.

Homocysteine

An amino acid that is not used to build proteins. Homocysteine is needed to make the amino acid methionine, which is used to make proteins. Homocysteine is also formed when methionine is broken down. Homocystinuria is a condition that occurs when homocysteine builds up.

Hormones

Chemical messengers in the body. Examples of hormones include aldosterone and cortisol.

Hydroxylysine

An amino acid that your body makes from lysine. Hydroxylysine is found in collagen, a protein present in our skin and bones.

Hydroxyurea

A medicine that can make red blood cells stay round and more flexible. It is used to treat some hemoglobin disorders.

Hyperalimentation

A nutritional formula that is given into the blood for someone who cannot receive food or fluids by mouth.

Hyperammonemia

High levels of ammonia in the blood. Hyperammonemia is a dangerous condition that can happen if ammonia is not removed from the body in urine.

Signs of hyperammonemia in babies include poor feeding, sleepiness, vomiting, seizures, and low body temperature.

Hyperbilirubinemia

High levels of bilirubin in the blood. Hyperbilirubinemia occurs when the liver cannot get rid of bilirubin. High bilirubin turns the skin and eyes yellow (jaundice).

Hyperplasia

When a part of the body keeps growing and becomes too large.

Hypoglycemia

Low blood sugar. Our bodies need blood sugar for energy, especially in our brain. When a condition prevents the body from breaking down food for energy, blood sugar can drop to dangerously low levels.

Signs of hypoglycemia in babies include poor feeding, shaking, pale or blue skin or lips, low energy, seizures, floppy arms and legs, low body temperature, and stopping breathing.

Hypotonia

Floppy arms and legs, weak muscle tone.

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I

Immunoglobulin replacement therapy

A treatment that adds antibodies (also called immunoglobulins) to your blood (intravenously) to help you fight infections. Sometimes called IVIG for intravenous immunoglobin.

Immunologist

A doctor with extra training in the immune system, the part of the body that fights infections.

In-range result

A result that is inside the range of expected results for typical babies. An in-range result means your baby likely does not have the condition that the screen is checking for.

Inherit

In medical terms, passing down genes from parents to children. Genes determine how your body develops, including your hair color, eye color, and whether you have certain genetic conditions.

Injection

When medicine is delivered into your body by a needle, often called a “shot.”

Insulin

A protein in the body that helps the body use sugar for energy and controls blood sugar levels. Higher insulin levels lead to lower blood sugar levels.

Intermittent

Comes and goes.

Intervention

An action taken to change a health outcome.

Intravenous

Delivered into your blood through a vein.

Involuntary

Movements that we do not make on purpose. For example, involuntary body movements include our heart beating. Sometimes problems in the brain can cause other movements to be involuntary, like twitches, spasms, or jerking our arms and legs.

Iodine

A mineral that is important for the thyroid gland to function.

Isoleucine

An amino acid that your body uses to build proteins.

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J

Jaundice

A condition where high amounts of bilirubin in the body turn the skin and/or eyes yellow or orange. Jaundice can happen in healthy babies soon after birth, especially if they are born early. Jaundice can also mean that the baby has an infection, liver issues, or a health condition.

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K

Kernicterus

A rare condition caused when high levels of bilirubin damage the brain.

Ketones

Your body makes ketones when it breaks down fat for energy. Ketones are usually made when the sugar in your blood is low (hypoglycemia).

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L

Lactose

A type of sugar present in milk and some products that are made from milk, like ice cream or cheese.

Lethargy

Sleepiness or lack of energy.

Leucine

An amino acid that your body uses to build proteins.

Leukodystrophy

A rare, inherited condition that causes damage to the brain’s myelin.

Lymph nodes

Small structures (glands) in the body that filter germs like bacteria and viruses out of our system.

Lymphocytes

Special white blood cells that the immune system uses to fight against germs that invade the body. Lymphocytes include T cells, B cells, and natural killer (NK) cells.

Lysine

An amino acid that your body uses to build proteins.

Lysosomal storage disorder

Lysosomes are tiny components in cells that contain enzymes that process nutrients. Lysosomal storage disorders are conditions where certain enzymes do not work. This causes unprocessed nutrients to build up, resulting in damage to many areas of the body.

Lysosomes

Special compartments inside your cells that process many nutrients your body needs.

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M

Macrocephaly

Large head size.

Macroglossia

Large tongue.

Magnetic resonance imaging (MRI)

A scan that makes detailed images of the inside of the body.

Medical geneticist

A doctor who has additional training in changes to our genes that can affect our health.

Medium chain triglyceride (MCT) oil

A medicine that contains a specific type of fat that is smaller than regular fats. It is given to babies that cannot digest fat from food easily. MCT oil provides your baby’s body with a fat that is easier to digest and turn into energy.

Metabolic crisis

A serious condition that can happen in people with a metabolic disorder. A metabolic crisis occurs when the blood sugar gets too low (hypoglycemia) and toxic substances like ammonia get too high (hyperammonemia).

Metabolic disorder

Metabolism is the complex process our bodies use to keep us alive. A metabolic disorder occurs when a change to this process makes it more difficult for the body to make energy and get rid of toxins. The RUSP has three categories of metabolic disorders: organic acid disorders, fatty acid disorders, and amino acid disorders.

Metabolism

Process of getting energy from food.

Methionine

An amino acid that your body uses to build proteins.

Microcephaly

Small head size.

Milestone

In medical terms, an action or event marking a major change or stage in development.

Milestone regression

Loss of developmental milestones. For example, a baby who was able to walk stops walking.

Mitochondria

Rod-shaped structure inside a cell. Mitochondria act like a digestive system, which takes in nutrients, breaks them down, and creates energy for the cell. Often called the powerhouse of the cell, mitochondria are in charge of releasing energy from food.

Monitor

In medical terms, when a health care provider keeps track of your baby’s overall health, symptoms, or test results.

Myelin

Protective covering of nerve cells.

Myopathic

Having weak muscles.

Myopia

Nearsighted. People with myopia can see well up close but have trouble seeing objects that are far away.

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N

Natural killer (NK) cells

Immune cells (lymphocytes) in the blood that can kill infectious cells without being activated by other cells.

Nausea

Feeling of stomach discomfort or wanting to vomit.

Neuromuscular disorder

A condition that causes problems with the nerves and muscles in your body.

Neurologist

A doctor with extra training on the brain, spinal cord, and nerves.

Neurotransmitters

Chemicals that carry messages from one part of the brain to another.

Newborn intensive care unit (NICU)

A unit in the hospital that cares for babies that need special help with staying warm, feeding, and other medical needs.

Newborn screening (NBS)

The process of checking babies to identify those who might have certain serious health conditions that can benefit from early treatment or intervention.

Newborn screening panel

A list of conditions for which newborns receive screening at or shortly after birth.

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O

Ophthalmologist

Eye doctor

Organic acid disorder

Conditions caused when the body has trouble breaking down fats and proteins and turning them into energy. Several genes make proteins (enzymes) that are needed for breaking down fats and proteins. When one of these genes does not work, it can cause an organic acid disorder. Also called organic acid condition.

Other disorder

Conditions that are found by newborn screening that do not fit into the condition categories of metabolic disorder, endocrine disorder, or hemoglobin disorder as defined by the ACHDNC.

Otoacoustic emissions (OAE)

A type of hearing screening method used to test an infant’s ability to hear.

Out-of-range result

A result that is outside the range of results for typical babies. An out-of-range result means your baby might have a condition and needs further testing.

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P

Pancreatic enzymes

Enzymes that the pancreas makes and puts into our intestines to help us digest food.

Peripheral

In medical terms, away from the center. For example, peripheral vision is what you see around all sides of what you are focusing on.

Peroxisomal disorder

Peroxisomes are tiny components in cells that help break down fats. Peroxisomal disorders are conditions that cause fats to build up in the cells. The buildup of fats causes damage to many areas of the body.

Peroxisomes

Tiny components in cells that help break down fats.

Phenylalanine

An amino acid that your body uses to build proteins.

Phenylketonuria (PKU)

A condition in which babies cannot process a specific amino acid called phenylalanine. It can cause serious health problems, including brain damage, if not treated early in life. 

Photophobia

Sensitivity to light.

Phototherapy

Treatment using light. For example, blue-green light is used to treat babies with high levels of bilirubin (jaundice). The light changes the bilirubin into a form that babies can get rid of through urine. Babies wear eye covers to protect their eyes during treatment. Health care providers check the babies’ blood to determine when the bilirubin has returned to safe levels. When used for jaundice, phototherapy is also called “bili lights.”

Pseudodeficiency

A type of false-positive that can occur during screening for certain conditions. Babies with pseudodeficiency have a change in one of their enzymes. Their enzyme works normally in the body, but the screen can only see that it is changed and cannot see that it is working. Babies with pseudodeficiency do not have the condition. Follow-up testing determines if your baby has the condition or has a pseudodeficiency.

Premature

Babies that were born early, before the 37th week of pregnancy.

Primary immune disorder

A condition that prevents the body from developing a normal immune system. Our immune system is needed to fight infections.

Profound

A severe form of a condition. For example, babies with profound hearing loss typically only experience loud sounds as vibrations.

Pulmonologist

A doctor with extra training in the lungs and airways.

Pulse oximetry

A test used to measure how much oxygen is in the blood.

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R

Reactive oxygen species

A type of unstable molecule that, at high levels, can damage cells.

Recommended Uniform Screening Panel (RUSP)

The list of conditions for which the United States Secretary of Health and Human Services recommends newborns receive screening. 

Red blood cells

Round red cells in your blood that use hemoglobin to carry oxygen from the lungs to the body and carry carbon dioxide from the body to the lungs.

Regenerate

To make again. For example, the process where your body recycles cofactors to use them again.

Retinopathy

Eye problems. Retinopathy is damage to the blood vessels in the back of the eye.

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S

Secretary of Health and Human Services (HHS)

The person who administers the United States Department of Health and Human Services (part of the U.S. government).

Seizure

A sudden change in the brain’s electricity. There are many types of seizures depending on what part of the brain is changing. Signs of a seizure in babies can include any one of the following: staring, rapid eye blinking, breathing problems, head nodding, jerking movements, becoming stiff, or passing out.

Sensor

A device that detects or measures something.

Septal defects

Holes in the heart. Ventricular septal defects are holes in the wall (septum) that separates the left and right lower chambers (ventricles) of the heart. Atrial septal defects are holes in the septum that separates the left and right upper chambers (atria) of the heart.

Sickle

A sickle shape is a curved shape, like a crescent moon or the letter C. When red blood cells are sickle-shaped instead of round, they break down more easily and can also get stuck in the blood vessels.

Sodium

An atom that your body uses to control fluid levels in cells. It is also needed for our muscles and nerves to work.

Spasm

Sudden muscle movements that we cannot control. They can occur in any muscle in the body, including the heart.

Spasticity

Muscle tightness or stiffness.

Specialist

A health care professional who has extra training and knowledge and whose practice is limited to a specific area of medicine.

Specimen

A sample used for testing. Examples include a dried blood spot, a tube of blood, a sample of urine, or a skin sample.

Spleen

An organ located under your ribs and above your stomach. The spleen gets rid of old or damaged red blood cells. The spleen also helps the immune system fight infection.

Sporadic

Happening sometimes with no pattern. A sporadic condition is not passed down from parent to child.

Statin

Medicine that lowers cholesterol levels.

Stem cell transplantation (SCT)

Stem cells can develop into any type of cell, such as blood cells, brain cells, heart muscle cells, or bone cells. Stem cell transplantation is the process of removing stem cells from a healthy person and injecting them into someone who needs them. Some conditions can be treated with stem cells.

Substrate reduction therapy

Medicine that prevents your body from making a substance. For example, in Gaucher disease, the body cannot break down glucocerebroside, a substance that your body uses in certain cell processes. Glucocerebroside builds up and causes damage. Substrate reduction therapy helps prevent the body from making glucocerebroside.

Succinylacetone

A substance formed when your body breaks down the amino acid tyrosine. Normally, the body breaks down succinylacetone rapidly. When a condition prevents that process, too much succinylacetone builds up and can damage the liver and kidneys.

Supplement

To add. In the case of many newborn conditions, your baby’s diet needs a supplement of an important nutrient or nutrients to help their body’s processes work better.

Syndrome

A group of symptoms that often occur together, or a condition that includes symptoms in different parts of the body.

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T

T cells

Immune cells (lymphocytes) in the blood that fight dangerous germs.

T cell receptor excision circles (TRECs)

Small pieces of extra, nonfunctional DNA that are present in the blood when the body is making T cells. Low levels of TRECs in newborns can mean that the immune system is not working as it should.

Tachypnea

Rapid or troubled breathing.

Tetrahydrobiopterin (BH4)

A type of biopterin that is naturally present in your body to help certain enzymes work (cofactor). It is also taken as a supplement to treat some conditions found by newborn screening.

Thiamine

Also called vitamin B-1, this vitamin is needed for certain enzymes to work (a cofactor).

Thrush

Patchy white dots in the mouth or throat that do not get better. Also called candidiasis. Thrush is an infection caused by yeast (a type of fungus).

Thymus

A small structure (gland) in your chest that functions until puberty. The thymus gland helps develop the immune system.

Thyroid gland

A butterfly-shaped organ in the neck. It makes hormones that help in growth and development. It is also important for many body processes that help you live, such as metabolism.

Total parenteral nutrition (TPN)

A nutritional formula that is given into the blood for someone who cannot receive food or fluids by mouth.

Trait

A feature that is a part of you, like the color of your eyes or how tall you are.

In hemoglobin disorders, a hemoglobin trait or sickle cell trait refers to having one hemoglobin gene that does not work. Everyone has two copies of each gene – one inherited from the mom and one inherited from the dad. People with a hemoglobin disorder have two nonworking hemoglobin genes. People with a hemoglobin trait have one normal hemoglobin gene and one gene that does not work. People with a hemoglobin trait usually do not have symptoms of a hemoglobin disorder.

Trait may also refer to sexual traits. Sexual traits are differences in your body that are a result of your biological sex (male or female). Chest hair is an example of a sexual trait because it is more often seen in biological males.

Transfusion

A medical procedure in which you receive healthy blood directly through a blood vessel (intravenous).

Transient

Temporary, not permanent.

Transplant

When a part of your body is replaced with a part from somewhere else, like a donation from another person. Examples of transplants related to newborn screening are liver, stem cell, bone marrow, or thymus transplants.

Transporter

A protein that helps substances move from one part of the cell to another.

Tryptophan

An amino acid that your body uses to build proteins.

Tyrosine

An amino acid that your body uses to build proteins.

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U

Unilateral

One side. For example, unilateral hearing loss occurs in one ear.

Uptake scan

A procedure that makes an image of the thyroid gland and also tests its function. The uptake test measures how much radioactive iodine the thyroid takes in. The scan checks the size, shape, and location of the thyroid.

Urea cycle

A process in which waste (ammonia) is turned into a less toxic form (urea). When you eat proteins, the body breaks them down into amino acids. Amino acids are broken down further into ammonia. Ammonia is toxic, so the urea cycle changes it to urea, which is removed from the body in your urine.

Urea cycle disorder

Condition caused when the urea cycle is not working. Several genes make proteins (enzymes) that are required for the urea cycle to remove ammonia (a waste product) from the body. When one of these genes does not make a working enzyme, it can cause a urea cycle disorder.

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V

Valine

An amino acid that your body uses to build proteins.

Variant

A different version. Hemoglobin variants are different versions of hemoglobin. Conditions may have variants that show different symptoms.

Gene variants are different versions of the same gene (previously called gene mutations).

Virilizing

The development of male sex characteristics (traits) like facial hair, typically because of too much of certain male sex hormones.

Voluntary

Movements that we mean to make, like when we want to pick something up and our hand closes around the object.

Vomiting

When the digestive system pushes food out of the mouth, also called “throwing up.”

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W

White blood cells

Cells in your blood that are part of the immune system. Lymphocytes, B cells, T cells, and natural killer (NK) cells are all white blood cells.

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X

X-linked recessive

One way a condition can run in families (inheritance pattern). Everyone has two copies of each gene – one inherited from the mom and one inherited from the dad. If a condition is X-linked, it means the gene lives on the X chromosome. If a condition is X-linked recessive, it means your baby can only have the condition if they do not have a working copy of the gene.

Biological girls have two X chromosomes and biological boys only have one X chromosome. This means girls who have one nonworking gene on the X chromosome can have a working copy of the gene on their second X chromosome. Boys who have a nonworking gene do not have a second (backup) working gene. X-linked conditions are often more frequent and more severe in boys because they do not have a backup X chromosome.

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