Alcohol related neurodevelopmental disorder (ARND): A diagnosis given when an individual has had prenatal alcohol exposure and has central nervous system damage (structural, neurological, and/or functional), but has no or has only minimal abnormal facial features or growth problems characteristic of fetal alcohol syndrome.;;

Alpha or beta thalassemia: Thalassemia results from a defect in a gene that helps to control the production of the two main proteins that make up hemoglobin, the alpha and the beta globins. The two main types of thalassemia, alpha and beta thalassemia, result from a missing or changed gene or gene related to the alpha globin protein or the beta globin protein, respectively. This leads to a deficiency of hemoglobin and anemia.

Amino acid:
“One of several molecules that join together to form proteins. There are 20 common amino acids found in proteins.”

Amniocentesis: “Prenatal diagnosis method using cells in the amniotic fluid to determine the number and kind of chromosomes of the fetus and, when indicated, perform biochemical studies.”

Anemia: “A condition in which the number of red blood cells is below normal.”
Physician Data Query via Unified Medical Language System at the National Library of Medicine.

Anencephaly: “Anencephaly is a defect in the closure of the neural tube during fetal development. The neural tube is a narrow channel that folds and closes between the 3rd and 4th weeks of pregnancy to form the brain and spinal cord of the embryo. Anencephaly occurs when the “cephalic” or head end of the neural tube fails to close, resulting in the absence of a major portion of the brain, skull, and scalp. Infants with this disorder are born without a large portion of their brains. A baby born with anencephaly is usually blind, deaf, unconscious, and unable to feel pain.”

Autosomes: “An autosome is any of the numbered chromosomes, as opposed to the sex chromosomes. Humans have 22 pairs of autosomes and one pair of sex chromosomes (the X and Y). Autosomes are numbered roughly in relations to their sizes. That is, Chromosome 1 has approximately 2,800 genes, while chromosomes 22 has approximately 750 genes.”


Biochemical: “Characterized by, produced by, or involving chemical reactions in living organisms”

Body mass index (BMI): “A measure of body fat that is the ratio of the weight of the body in kilograms to the square of its height in meters (a body mass index in adults of 25 to 29.9 is considered an indication of overweight, and 30 or more an indication of obesity).”


Canavan: “Canavan disease is an inherited disorder that causes progressive damage to nerve cells in the brain. This disease is one of a group of genetic disorders called leukodystrophies. Leukodystrophies are characterized by degeneration of myelin, which is the fatty covering that insulates nerve fibers.”

Carriers: “A carrier is an individual who carries and is capable of passing on a genetic mutation associated with a disease and may or may not display disease symptoms. Carriers are associated with diseases inherited as recessive traits. In order to have the disease, an individual must have inherited mutated alleles from both parents.”

Chorionic villus sampling: “An invasive prenatal diagnostic procedure involving removal of villi from the human chorion [a membrane surrounding the embryo that contributes to the formation of the placenta] to obtain chromosomes and cell products for diagnosis of disorders in the human embryo.”

Chromosome: “DNA is packaged into small units called chromosomes. A chromosome contains a single, long piece of DNA with many different genes. Every human cell contains 23 pairs of chromosomes. There are 22 pairs of numbered chromosomes, called autosomes, and one pair of sex chromosomes, which can be XX or XY. Each pair contains two chromosomes, one from each parent, which means that children get half of their chromosomes from their mother and half from their father.”

Congenital anomalies: “Congenital anomalies are also known as birth defects, congenital disorders or congenital malformations. Congenital anomalies can be defined as structural or functional anomalies, including metabolic disorders, which are present at the time of birth.”

Congenital heart defects: “Congenital heart defects are problems with the heart’s structure that are present at birth. These defects can involve the interior walls of the heart, the valves inside the heart, or the arteries and veins that carry blood to the heart or the body.”

Congenital hyperthyroidism: “Congenital hypothyroidism is a condition that affects infants from birth (congenital) and results from a partial or complete loss of thyroid function (hypothyroidism). The thyroid gland is a butterfly-shaped tissue in the lower neck. It makes iodine-containing hormones that play an important role in regulating growth, brain development, and the rate of chemical reactions in the body (metabolism).”

Cystic fibrosis: “An autosomal recessive genetic condition of the exocrine glands, which causes the body to produce excessively thick, sticky mucus that clogs the lungs and pancreas, interfering with breathing and digestion.”

Cytogenetic: “Of or pertaining to cytogenesis or cell development.”


Down syndrome: “Down syndrome is a genetic disease resulting from a chromosomal abnormality. An individual with Down syndrome inherits all or part of an extra copy of Chromosome 21. Symptoms associated with the syndrome include mental retardation, distinctive facial characteristics, and increased risk for heart defects and digestive problems, which can range from mild to severe. The risk of having a child with Down syndrome rises with the mother’s age at the time of conception.”

Dysmorphic: “Characterized by malformation.”


Epigenome: “The term epigenome is derived from the Greek word epi which literally means “above” the genome. The epigenome consists of chemical compounds that modify, or mark, the genome in a way that tells it what to do, where to do it, and when to do it. Different cells have different epigenetic marks. These epigenetic marks, which are not part of the DNA itself, can be passed on from cell to cell as cells divide, and from one generation to the next.”


Familial Dysautonomia: Familial dysautonomia is a genetic disorder that affects the development and survival of certain nerve cells. The disorder disturbs cells in the autonomic nervous system, which controls involuntary actions such as digestion, breathing, production of tears, and the regulation of blood pressure and body temperature. It also affects the sensory nervous system, which controls activities related to the senses, such as taste and the perception of pain, heat, and cold. Familial dysautonomia is also called hereditary sensory and autonomic neuropathy, type III.”

Familial hypercholesterolemia: “Familial hypercholesterolemia is an inherited condition that causes high levels of LDL (low density lipoprotein) cholesterol levels beginning at birth, and heart attacks at an early age.”

Familial polyposis: “Familial polyposis is an inherited condition which primarily affects the large intestine (colon and rectum). Large numbers of projecting masses of swollen and thickened or tumorous membrane (polyps) develop on the inner lining of this part of the bowel. The polyps eventually become malignant.”

Fanconi anemia: “Fanconi’s anemia is a disease passed down through families (inherited) that mainly affects the bone marrow. It results in decreased production of all types of blood cells. Fanconi’s anemia is different from Fanconi syndrome, a rare kidney disorder. […]
Fanconi’s anemia is due to an abnormal gene that damages cells, which keeps them from repairing damaged DNA.”

Fetal alcohol syndrome (FAS): “A condition occurring in a fetus or newborn due to in utero ethanol exposure when the mother consumed alcohol during pregnancy. It is characterized by a cluster of irreversible birth defects including abnormalities in physical, mental, and behavior development (such as fetal growth retardation; mental retardation; attention deficit and disruptive behavior disorders) with varied degree of severity in an individual.” MeSH via Unified Medical Language System at the National Library of Medicine.

Fragile X syndrome: “Fragile X syndrome is a genetic condition that causes a range of developmental problems including learning disabilities and cognitive impairment. Usually, males are more severely affected by this disorder than females.”


Gastroschisis: A defect present at birth, characterized by a separation in the abdominal wall, forming an opening through which the abdominal contents (the intestines) protrude.

Genome: “The genome is the entire set of genetic instructions found in a cell. In humans, the genome consists of 23 pairs of chromosomes, found in the nucleus, as well as a small chromosome found in the cells’ mitochondria. These chromosomes, taken together, contain approximately 3.1 billion bases of DNA sequence.”


Hemoglobin: “A protein inside red blood cells that carries oxygen from the lungs to tissues and organs in the body and carries carbon dioxide back to the lungs.”

Hemophilia: “Hemophilia is an inherited disease, most commonly affecting males, that is characterized by a deficiency in blood clotting. The responsible gene is located on the X chromosome, and since males inherit only one copy of the X chromosome, if that chromosome carries the mutated gene then they will have the disease. Females have a second, usually normal, copy of the gene on their other X chromosome, so they capable of passing on the disease without experiencing its symptoms.”


Immune mediated conditions: “Conditions resulting from tissue damage caused by the body’s immune system.”

In vitro fertilization: “In vitro fertilization (IVF) is a procedure in which eggs (ova) from a woman’s ovary are removed. They are fertilized with sperm in a laboratory procedure, and then the fertilized egg (embryo) is returned to the woman’s uterus.”


Medium-chain acyl-CoA dehydrogenase deficiency: MCAD deficiency (or MCADD) is a condition whereby certain fats in the body cannot be converted into energy and often occurs during periods of fasting. MCADD symptoms, often occurring during infancy or early childhood, include vomiting and having low energy and/or low blood sugar levels. There are a wide range of potential complications, from having difficulty breathing to coma and death.

Molecular: “Of, relating to, or consisting of molecules.”
Multifactorial: “a characteristic influenced in its expression by many factors, both genetic and environmental.”


Neural tube defects: Congenital defects resulting from incomplete closure of the neural tube during the early phases of development of the embryo.

Nucleus: “A nucleus is a membrane-bound organelle that contains the cell’s chromosomes. Pores in the nuclear membrane allow for the passage of the molecules in and out of the nucleus,”


Orphan disease: “A disease that is so rare that it is not considered commercially viable to develop drugs to treat it.”


Partial fetal alcohol spectrum disorder (PFAS of Partial FAS): The classification when an individual does not have all of the symptoms of fetal alcohol syndrome (FAS) but has been exposed to alcohol prenatally and meets some of the criteria for FAS. Specifically, this
person may have some of the facial abnormalities of FAS, a growth deficiency, and central nervous system damage.;

Phenylalanine: “An essential aromatic amino acid in humans (provided by food), Phenylalanine plays a key role in the biosynthesis of other amino acids and is important in the structure and function of many proteins and enzymes. Phenylalanine is converted to tyrosine, used in the biosynthesis of dopamine and norepinephrine neurotransmitters.” From the NCI Thesaurus via Unified Medical Language System at the National Library of Medicine (

Phenylalanine hydroxylase (PAH): “PAH is an enzyme responsible for the first step in processing phenylalanine, a building block of proteins (amino acids) obtained through consumption of all proteins and certain artificial sweeteners. Phenylalanine hydroxylase is responsible for the conversion of phenylalanine to another amino acid, tyrosine.[…] Tyrosine is used to make several types of hormones, certain chemicals that transmit signals in the brain (neurotransmitters), and a pigment called melanin, which gives hair and skin their color. Tyrosine can also be broken down into smaller molecules that are used to produce energy.[…] Phenylketonuria results from mutations in the PAH gene.” .

Phenylketonuria (PKU): “Phenylketonuria is a rare metabolic disorder that affects the way the body breaks down protein [the protein phenylalanine]. If not treated shortly after birth, PKU can be destructive to the nervous system, causing mental retardation.”


Retinoblastoma: “Retinoblastoma is a rare type of eye cancer that usually develops in early childhood, typically before the age of 5. This form of cancer develops in the retina, which is the specialized light-sensitive tissue at the back of the eye that detects light and color.”


Sickle cell anemia: “A hereditary, chronic form of hemolytic anemia characterized by breakdown of the red blood cells; red blood cells undergo a reversible alteration in shape when the oxygen tension of the plasma falls slightly and a sickle-like shape forms.”


Tandem mass spectrometry: A method for examining a sample for certain substances, using a mass spectroscope for each step. First, a group of ions is selected for fragmentation, then, mass spectra (a pattern showing the distribution of ions by their mass) are created for the fragments. This procedure is used to screen newborns for various metabolic disorders using a sample of their blood.

Tay-Sachs disease: A rare but fatal degenerative autosomal recessive disorder that progressively destroys nerve cells (neurons) in the brain and spinal cord, causing mental deficiency, paralysis, mental deterioration, and blindness. Tay-Sachs is found primarily but not exclusively among Ashkenazi Jews, and the most common form of the disease becomes apparent in infancy.”;

Thalassemia: “Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form of hemoglobin, the protein in red blood cells that carries oxygen. The disorder results in excessive destruction of red blood cells, which leads to anemia.”

Trisomy 13: “Trisomy 13, also called Patau syndrome, is a chromosomal condition associated with severe intellectual disability and physical abnormalities in many parts of the body. Individuals with trisomy 13 often have heart defects, brain or spinal cord abnormalities, very small or poorly developed eyes (microphthalmia), extra fingers and/or toes, an opening in the lip (a cleft lip) with or without an opening in the roof of the mouth (a cleft palate), and weak muscle tone (hypotonia). Due to the presence of several life-threatening medical problems, many infants with trisomy 13 die within their first days or weeks of life. Only five percent to 10 percent of children with this condition live past their first year.”

Trisomy 18: Trisomy 18, also called Edwards syndrome, is a genetic disorder in which a person has a third copy of material from chromosome 18 rather than the usual two copies. This leads to abnormalities in several body parts, such as having heart defects, clenched hands, feet with a rounded bottom, mental delay, and a small head size, among others. Affected individuals have slow intrauterine development and a low birth weight, and many die before birth.;

Turner syndrome: “Turner syndrome is a chromosomal condition that alters development in females. Women with this condition tend to be shorter than average and are usually unable to conceive a child (infertile) because of an absence of ovarian function. Other features of this condition that can vary among women who have Turner syndrome include: extra skin on the neck (webbed neck), puffiness or swelling (lymphedema) of the hands and feet, skeletal abnormalities, heart defects and kidney problems.”


X-linked condition: “X-linked is a trait where a gene is located on the X chromosome. Humans and other mammals have two sex chromosomes, the X and the Y. In an X-linked or sex-linked disease, it is usually males that are affected because they have a single copy of the X chromosomes that carries the mutation. In females, the effect of the mutation may be masked by the second healthy copy of the X chromosome.”