Ambiguous genitalia is a condition in which a newborn's external genitals don't appear clearly male or female.
A rare genetic disorder, Angelman syndrome causes a variety of problems, such as developmental delays, speech impairment, and difficulty with movement and balance.
Ataxia describes lack of muscle coordination while performing voluntary movements. A sign of an underlying condition, ataxia can affect any part of your body.
Brugada syndrome is a serious, genetic disorder that can cause life-threatening heart rhythm disturbances. It's treatable with medical devices.
Cerebral palsy — Comprehensive overview covers symptoms, causes and treatment of this movement disorder.
Charcot-Marie-Tooth disease includes a group of disorders that affect the peripheral nerves, causing muscle weakness and loss of muscle bulk. Treatment focuses on managing symptoms.
Childhood disintegrative disorder is a developmental disorder characterized by normal development of at least two years, followed by loss of language, social and motor skills.
Colon polyps — small clumps of cells on your colon lining — are usually harmless, but some may become cancerous over time.
Congenital adrenal hyperplasia is a genetic condition affecting the adrenal glands and interfering with normal growth and development in boys and girls.
Craniosynostosis is a birth defect in which one or more of the bony plates of a baby's skull fuse prematurely, misshaping the head.
Earlier detection and better treatments have improved the outlook for people with cystic fibrosis.
Diabetes insipidus is a rare condition characterized by intense thirst and the excretion of large amounts of urine.
DiGeorge syndrome, a disorder due to "missing" genes, can result in numerous problems, including heart defects, low blood-calcium levels, delayed speech development and behavioral disorders.
Dilated cardiomyopathy is a disease of the heart in which the heart's main pumping chamber becomes enlarged and doesn't pump blood efficiently.
Down syndrome is a genetic disorder that results in mental retardation and other problems. Children with Down syndrome often benefit from early intervention and education.
Dwarfism — an adult height of 4 feet 10 inches (147 centimeters) or less — is caused by a medical or genetic condition.
Ehlers-Danlos syndrome (EDS) includes a group of uncommon genetic disorders that mainly affect the joints, skin and walls of blood vessels.
Epidermolysis bullosa is a group of inherited skin diseases whose hallmark is fragile skin that blisters easily. Severe forms may be life-threatening.
Essential thrombocythemia is an uncommon blood disorder in which your body makes too many platelets, which can cause abnormal blood clotting or bleeding.
Factor V Leiden is an inherited disorder that results in an increased risk of blood clots. There's no cure, but blood-thinning medication can lower the risk of clotting.
Gaucher's disease is an inherited disorder in which fatty substances accumulate in abnormal amounts in your body, affecting the functioning of organs.
Hemochromatosis causes your body to store large amounts of iron, which can cause life-threatening complications. The simple treatment is to regularly remove blood.
Huntington's disease — an inherited disease that causes the degeneration of brain cells — results in movement, psychiatric, cognitive disorders and eventual death.
Hypertrophic cardiomyopathy is a genetic disorder in which heart muscle becomes abnormally thick. It's the most common cause of sudden cardiac death in young people.
If you've tried to conceive for more than a year, you or your partner may be experiencing infertility.
Klinefelter syndrome is a genetic disorder that affects hormone levels in males. Discover what causes it — and what treatments are available.
Krabbe disease is a rare, inherited disorder that impairs functioning of the central nervous system, and most often affects infants, leading to early death.
Long QT syndrome is an electrical disturbance that can cause sudden, rapid heart rates. It can be genetic or a side effect of medication.
Low sperm count can cause male infertility. Find out what causes it and how it's treated.
Lynch syndrome, an uncommon disorder caused by genetic defects, predisposes a person to develop colon cancer and other forms of cancer.
Male hypogonadism (testosterone deficiency) affects the development of male physical characteristics, sex drive, fertility and sense of well-being. Treatment may involve testosterone replacement therapy.
You and your partner want a baby — but your sperm needs help getting the job done. Most couples can still make it happen with the right treatment.
Marfan syndrome, a connective tissue disorder, can affect almost any part of your body, including your heart, eyes and ligaments.
Muscular dystrophy is an inherited disease resulting in progressive weakness of the body's muscles. Some forms are milder; others, more severe.
In myelofibrosis, healthy bone marrow is replaced with scar tissue, leading to severe anemia and fatigue.
Neurofibromatosis — Comprehensive overview covers symptoms, diagnosis and treatment of this genetic disorder.
Noonan syndrome is caused by a mutation in one of the genes responsible for normal development in many parts of the body, including the heart.
Phenylketonuria is a rare birth defect for which newborns are routinely screened. This rare birth defect requires a special diet to prevent mental retardation.
A pheochromocytoma is a rare adrenal gland tumor that can produce large amounts of certain hormones and seriously raise blood pressure.
Polycythemia vera is a rare blood disorder in which a person's bone marrow makes too many blood cells.
Prader-Willi syndrome, a genetic disorder characterized by decreased muscle tone and a constant desire to eat, often leads to morbid obesity.
If you've had a miscarriage and want to get pregnant again, you might have questions. Find out more about pregnancy after miscarriage.
Primary progressive aphasia is a rare neurological syndrome that slowly and progressively impairs language capabilities.
Progeria is a rare genetic disorder that causes premature, rapid aging in children. Progeria results from a single gene mutation.
High blood pressure affecting only the arteries in your lungs is known as pulmonary hypertension. Discover the symptoms, risk factors and treatment for this condition.
Parenting a child with Rett syndrome can be challenging. Here's what to expect and steps you can take to help your child.
Stickler syndrome can affect multiple parts of your body, including your eyes, face, ears, bones and joints.
Thalassemia is an inherited blood disorder, characterized by less hemoglobin and fewer red blood cells than normal. When necessary, treatment includes blood transfusions.
An often silent killer, a thoracic aortic aneurysm may cause no symptoms until it ruptures, causing life-threatening bleeding.
How to identify and treat triple X syndrome.
Turner syndrome, a genetic condition that only affects females, results in poor growth, poor development of adult sex characteristics, infertility and other medical problems.
In Wilson's disease, the body doesn't metabolize copper properly, causing excess amounts to accumulate in the liver and other organs.
Jul. 19, 2013
- Handbook — Help me understand genetics. Genetics Home Reference. http://ghr.nlm.nih.gov/handbook/. Accessed May 7, 2013.
- Frequently asked questions about genetic testing. National Human Genome Research Institute. http://www.genome.gov/19516567. Accessed May 7, 2013.
- Raby BA, et al. Genetic counseling and testing. http://www.uptodate.com/home. Accessed May 8, 2013.
- Grody WW, et al. ACMG position statement on prenatal/preconception expanded carrier screening. American College of Medical Genetics and Genomics. Genetics in Medicine. In press. Accessed May 8, 2013.
- Harms RW (expert opinion). Mayo Clinic, Rochester, Minn. May 10, 2013.