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Comprehensive
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Comprehensive
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Comprehensive
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Disease List:

3 6 A B C D E F G H I J K L M N O P R S T U V W Z

Glycogen Storage Disease, Type 3

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What is Glycogen Storage Disease, Type 3?

Glycogen Storage Disease, Type 3, also called GSD3, is an autosomal recessive disorder in which the body is unable to break down the stored form of sugar called glycogen. This causes glycogen to build up in body cells and results in damage to certain organs and tissues, especially the liver and muscles.

Infants with Glycogen Storage Disease, Type 3 may have low blood sugar (hypoglycemia), high cholesterol, and high liver enzymes. Children with Glycogen Storage Disease, Type 3 commonly develop an enlarged liver, leading to a noticeably swollen abdomen. Liver size usually returns to normal later in childhood, but long term liver damage may occur. A slower than average growth rate, muscle weakness, and an enlarged heart are also common in children with Glycogen Storage Disease, Type 3.  In rare cases symptoms may be milder and may not occur until adulthood.  Medical and dietary treatments often lessen the effects of Glycogen Storage Disease, Type 3.

What causes Glycogen Storage Disease, Type 3?

Glycogen Storage Disease, Type 3 is caused by a gene change, or mutation, in both copies of the AGL gene pair. These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, it leads to the symptoms described above.

Glycogen Storage Disease, Type 4

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What is Glycogen Storage Disease, Type 4?

Glycogen Storage Disease, Type 4, also called Andersen disease or GSD4, is an autosomal recessive disorder caused by the lack of a particular enzyme called glycogen branching enzyme. The absence of this enzyme causes glycogen – a form of stored sugar that is broken down by the body and used for energy in the cells – to build up in the body.  This buildup leads to scarring (cirrhosis) and damage of the tissues and organs where glycogen is stored, especially the liver and muscles. 

There are many forms of Glycogen Storage Disease, Type 4 and the symptoms range from mild to severe. Glycogen Storage Disease, Type 4 often causes symptoms in infancy with poor feeding and growth (failure to thrive), an enlarged liver and spleen, enlarged heart, low muscle tone (hypotonia), and muscle wasting. Liver cirrhosis appears very early, worsens with age, and can lead to death before age five. Childhood symptoms of Glycogen Storage Disease, Type 4 may include muscle weakness and heart disease that worsen as the child gets older.  Lifespan is typically shortened in the more severe forms of Glycogen Storage Disease, Type 4.

Rarely, specific mutations in the same gene cause a different disorder called Adult Polyglucosan Body Disease.  Symptoms of this condition typically start in mid-adulthood and include peripheral neuropathy (loss of sensation in the arms and legs due to progressive breakdown of the nerves), impairment of the nerves of the bladder, muscle weakness and stiffness.  Some people with this condition also develop dementia.  It is sometime, but not always, possible to tell whether a specific gene mutation will cause Glycogen Storage Disease, Type 4 or Adult Polyglucosan Body Disease.

What causes Glycogen Storage Disease, Type 4?

Glycogen Storage Disease, Type 4 is caused by a change, or mutation, in both copies of the GBE1 gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of the GBE1 gene do not work correctly, it leads to the symptoms described above.

Glycogen Storage Disease, Type 5 (McArdle Disease)

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What is Glycogen Storage Disease, Type 5 (McArdle Disease)?

Glycogen Storage Disease, Type 5, also called McArdle disease or GSD5, is an autosomal recessive disorder in which the body cannot change glycogen to glucose, the sugar used by the body for energy. This leads lack of enough energy for muscle cells to work properly. The symptoms of Glycogen Storage Disease, Type 5 can vary from mild to severe and commonly occur in young adults between the ages of 20 and 30.  Symptoms include muscle cramping, pain, weakness, soreness, and fatigue when exercising. Individuals with this disorder may also experience blood in the urine and temporary kidney failure.

What causes Glycogen Storage Disease Type 5 (McArdle Disease)?

Glycogen Storage Disease, Type 5 is caused by a change, or mutation, in both copies of the PYGM gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, it leads to the symptoms described above.

Glycogen Storage Disease, Type 7

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What is Glycogen Storage Disease, Type 7?

Glycogen Storage Disease Type 7, also referred to as Tarui Disease or GSD7, is an autosomal recessive disorder caused by the lack of an enzyme which is needed to breakdown glycogen, a stored form of sugar used for energy in muscle cells during exercise. GSD7 usually begins in childhood with symptoms of muscle weakness, pain and stiffness during exercise, nausea and vomiting, and dark red-colored urine. Breakdown of muscle tissue can also occur. A rare form of GSD7 occurs in infants that causes progressive loss of muscle tone (hypotonia), muscle weakness, and death. A late-onset form occurs in adults who experience only muscle weakness.

What causes Glycogen Storage Disease, Type 7?

GSD7 is caused by a gene change, or mutation, in both copies of the PFKM gene pair. These mutations cause the genes to not work properly or not work at all. When both copies of this gene do not work correctly, it leads to the symptoms described above.

GRACILE Syndrome

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What is GRACILE Syndrome?

GRACILE Syndrome, also known as Mitochondrial Respiratory Chain Complex III Deficiency, is an autosomal recessive disorder in which the parts of the cells in the body that make energy (the mitochondria) do not work properly. GRACILE Syndrome stands for Growth Retardation, Aminoaciduria, Cholestasis, Iron overload, Lactic acidosis, and Early death. Signs and symptoms begin during pregnancy and continue in infancy and include failure to grow and gain weight at the normal rate. Iron builds up in the liver leading to liver damage. Affected infants also have a buildup of a toxic substance called lactic acid in the blood. Kidney problems also develop. Due to the severe health problems caused by GRACILE Syndrome, affected infants usually die within the first days or months of life. Currently there is no cure for this condition.

Rarely, changes, or mutations, in the same gene cause a different inherited disorder called Bjornstad Syndrome. Symptoms of Bjornstad Syndrome include unusual twisted, brittle hair (pili torti) and hearing loss starting in childhood that may be mild to severe.

What causes GRACILE Syndrome?

GRACILE Syndrome is caused by mutations in both copies of the BCS1L gene pair. These mutations cause the genes to not work properly or not work at all. When both copies of the BCS1L gene do not work correctly, the mitochondria do not work properly, leading to the symptoms described above.

Guanidinoacetate Methyltransferase Deficiency

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What is Guanidinoacetate Methyltransferase Deficiency?

Guanidinoacetate Methyltransferase Deficiency is an autosomal recessive disorder that affects the brain and muscles. Symptoms of this disorder are usually first observed in infancy or childhood and include epileptic seizures, intellectual disability, difficulty with speech, and autistic-like behaviors. Other symptoms may also occur including muscle weakness, delayed motor skills, and involuntary movements such as tremors. Children with this condition who receive early treatment may have less severe symptoms and, in some cases, may show normal development.

What causes Guanidinoacetate Methyltransferase Deficiency?

Guanidinoacetate Methyltransferase Deficiency is caused by a change, or mutation, in both copies of the GAMT gene pair. These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, it leads to the symptoms described above.

Hemochromatosis Type 2A

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What is Hemochromatosis Type 2A?

Hemochromatosis Type 2A, also called Juvenile Hemochromatosis, is an autosomal recessive iron overload disorder in which the body absorbs too much iron from food. This extra iron is stored in the organs and causes damage, especially in the liver, skin, pancreas, heart, joints, and testes. If the condition is not treated, signs and symptoms of Hemochromatosis Type 2A begin in early childhood. Too much iron in the body causes joint pain (arthritis), liver disease, diabetes, skin discoloration, excessive tiredness, and heart disease that usually becomes severe by age 30. Decreased function of the ovaries and testes, known as hypogonadism, is also common. This leads to a loss of menstrual cycles for women and a delay in puberty or lowered sex drive for men.  If the condition is not treated, lifespan is shortened.  Treatment with periodic blood withdrawal, which removes the excess iron, is helpful in preventing or slowing the onset and severity of symptoms but cannot reverse damage that has already occurred.

What causes Hemochromatosis Type 2A?

Hemochromatosis Type 2A is caused by a gene change, or mutation, in both copies of the HFE2 gene pair. These mutations cause the genes to not work properly or not work at all.  When both copies of this gene pair are not working correctly it leads to the symptoms described above.

Hemochromatosis, Type 3, TFR2-Related

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What is Hemochromatosis, Type 3, TFR2-Related?

Hemochromatosis, Type 3, TFR2-Related is an autosomal recessive iron overload disorder in which the body absorbs too much iron from food. This extra iron is stored in the organs and causes damage, especially in the liver, skin, pancreas, heart, joints, and testes. If the condition is not treated, signs and symptoms of Hemochromatosis, Type 3, TFR2-Related usually begin before age 30. Too much iron in the body causes liver disease, diabetes, skin discoloration, excessive tiredness, joint pain (arthritis), and heart disease. Decreased function of the ovaries and testes, known as hypogonadism, is also common. This leads to a decrease in menstrual cycles for women and lowered sex drive for men. Treatment with periodic blood withdrawal, which removes the excess iron, is very effective at preventing new symptoms but cannot reverse damage that has already occurred.

What causes Hemochromatosis, Type 3, TFR2-Related?

Hemochromatosis, Type 3, TFR2-Related is caused by a gene change, or mutation, in both copies of the TFR2 gene pair. These mutations cause the genes to not work properly or not work at all.  When both copies of this gene pair do not work correctly, it leads to the symptoms described above.

Hepatocerebral Mitochondrial DNA Depletion Syndrome, MPV17-Related

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What is Hepatocerebral Mitochondrial DNA Depletion Syndrome, MPV17-Related?

Hepatocerebral Mitochondrial DNA Depletion Syndrome, MPV17-Related (also called Mitochondrial DNA Depletion Syndrome 6) is an autosomal recessive disorder that causes liver disease and neurological problems. Symptoms usually start shortly after birth and include vomiting, lack of energy, low blood sugar (hypoglycemia), diarrhea, and poor growth. Enlargement of the liver and liver disease also occur and worsen quickly, often leading to liver failure. Neurologic problems include muscle weakness, developmental delay, and a loss of sensation in the arms and legs. There is no treatment for this condition and infants with Hepatocerebral Mitochondrial DNA Depletion Syndrome, MPV17-Related usually do not live past early childhood.

What causes Hepatocerebral Mitochondrial DNA Depletion Syndrome, MPV17-Related?

Hepatocerebral Mitochondrial DNA Depletion Syndrome, MPV17-Related is caused by a change, or mutation, in both copies of the MPV17 gene pair. These mutations cause the genes to not work properly or not work at all. When both copies of this gene do not work correctly, it leads to the symptoms described above.

Hereditary Fructose Intolerance

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What is Hereditary Fructose Intolerance?

Hereditary Fructose Intolerance is an autosomal recessive disorder in which the body is unable to use fructose, a sugar found in many fruits as well as table sugar (sucrose).  People who have Hereditary Fructose Intolerance become sick when they eat foods containing fructose or sucrose.  Symptoms can be mild or severe.  If untreated, the condition can lead to some or all of the following after eating foods with fructose or sucrose:  hypoglycemia (low blood sugar), sweating, confusion, seizures, kidney damage, liver failure, and coma.   Hereditary Fructose Intolerance can be life-threatening in infants and ranges from mild to severe in older children and adults.  Early diagnosis and diet changes begun in infancy can reduce and often prevent these more serious problems.

What causes Hereditary Fructose Intolerance?

Hereditary Fructose Intolerance is caused by a gene change, or mutation, in both copies of the ALDOB gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, fructose builds up in the body and, if untreated, results in the symptoms described above. 

Hereditary Spastic Paraparesis, Type 49

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What is Hereditary Spastic Paraparesis, Type 49?

Hereditary Spastic Paraparesis, Type 49 is autosomal recessive.  It is one of a group of hereditary disorders that affect the muscles of the hips and legs. Symptoms of Hereditary Spastic Paraparesis, Type 49 usually start in infancy. Symptoms vary from person to person but typically include delayed walking, balance problems, muscle stiffness (spasticity) and weakness in the legs, developmental delay with intellectual disability, distinct facial features, and short stature. The muscle weakness and spasticity worsens over time. Currently there is no cure or specific treatment for this condition.

What causes Hereditary Spastic Paraparesis, Type 49?

Hereditary Spastic Paraparesis, Type 49 is caused by a gene change, or mutation, in both copies of the TECPR2 gene pair.  These mutations cause the genes to not work properly or not work at all.  If both copies of this gene do not work correctly, it leads to the symptoms described above.

Hermansky-Pudlak Syndrome, HPS1-Related

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What is Hermansky-Pudlak Syndrome, HPS1-Related?

Hermansky-Pudlak Syndrome, HPS1-Related is an autosomal recessive disorder that causes albinism (decreased color, or pigment, in the skin, hair, and eyes), bleeding problems, and may cause pulmonary fibrosis (scarring in the lungs).  The lack of pigment (albinism) causes abnormal eye movements (nystagmus), vision problems, and an increased risk for skin cancer. People with this condition also have problems with blood clotting, leading to bruising and easy bleeding.  Pulmonary fibrosis occurs in some people and typically begins in around the age of 30; the lung scarring leads to breathing problems that often result in death within about ten years after symptoms begin.

What causes Hermansky-Pudlak Syndrome, HPS1-Related?

Hermansky-Pudlak Syndrome, HPS1-Related is caused by a gene change, or mutation, in both copies of the HPS1 gene pair.  The function of the HPS1 gene pair is to help make pigment in the skin, hair and eyes, as well as to help with blood clotting.  When both copies of the HPS1 gene are not working correctly, it causes the symptoms described above. 

Hermansky-Pudlak Syndrome, HPS3-Related

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What is Hermansky-Pudlak Syndrome, HPS3-Related?

Hermansky-Pudlak Syndrome, HPS3-Related is an autosomal recessive disorder that causes albinism, eye problems, and bleeding problems. Albinism leads to decreased pigment, or color, in the skin, hair, and eye. Due to the reduced pigment, people with this disorder are at increased risk for skin cancer, abnormal eye movements (nystagmus), and vision loss.  Blood clotting problems may also occur.

What causes Hermansky-Pudlak Syndrome, HPS3-Related?

Hermansky-Pudlak Syndrome, HPS3-Related is caused by a gene change, or mutation, in both copies of the HPS3 gene pair.  These mutations cause the genes to not work properly or not work at all. The function of the HPS3 gene pair is to help make pigment in the skin, hair and eyes, as well as to help with blood clotting.  When both copies of the HPS3 gene are not working correctly, it causes the symptoms described above. 

Holocarboxylase Synthetase Deficiency

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What is Holocarboxylase Synthetase Deficiency?

Holocarboxylase Synthetase Deficiency, also called Multiple Carboxylase Deficiency, is an autosomal recessive disorder in which the body cannot properly use a B vitamin called biotin.  The disorder is easily and effectively treated with large doses of oral biotin prescribed by a doctor.  If treatment is not started early, signs and symptoms typically appear in the first few months of life but may also begin later in childhood. If untreated, Holocarboxylase Synthetase Deficiency can cause delayed development, seizures, weak muscle tone (hypotonia), breathing problems, hearing and vision loss, movement and balance problems, skin rashes, hair loss, and yeast infections.  Lifelong treatment with biotin supplementation can prevent the symptoms from occurring. With early diagnosis and treatment with biotin, people with Holocarboxylase Synthetase Deficiency can live healthy lives.

What causes Holocarboxylase Synthetase Deficiency?

Holocarboxylase Synthetase Deficiency is caused by a gene change, or mutation, in both copies of the HLCS gene pair. These mutations cause the genes to not work properly or not work at all. When both copies of this gene do not work correctly, it leads to the symptoms described above.

Homocystinuria due to Deficiency of MTHFR

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What is Homocystinuria due to Deficiency of MTHFR?

Homocystinuria due to Deficiency of MTHFR is an autosomal recessive disorder that causes an abnormal buildup of the amino acid homocystine and a decreased amount of the amino acid methionine in the blood. Signs and symptoms of Homocystinuria due to Deficiency of MTHFR often start in infancy but can start as late as adolescence.  Symptoms can include breathing problems, developmental delays, intellectual disabilities, movement problems, seizures, abnormal blood clotting and strokes, a small head size, and psychiatric disorders. Symptoms usually start within the first year of life. Medical treatment to attempt to reduce symptoms includes amino acid supplements (including high dose betaine), vitamin B12, folic acid, and other supplements.

What causes Homocystinuria due to Deficiency of MTHFR?

Homocystinuria due to Deficiency of MTHFR is caused by a gene change, or mutation, in both copies of the MTHFR gene pair. These mutations cause the genes to not work properly or not work at all. When both copies of the MTHFR gene pair do not work correctly, homocystine builds up in the blood and the amount of folate decreases, which leads to the symptoms described above.

Homocystinuria, CBS-Related

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What is Homocystinuria, CBS-Related?

Homocystinuria, CBS-Related is an autosomal recessive disorder that causes an abnormal buildup of the amino acid homocystine and other toxic substances in the blood. The severity and number of symptoms varies from person to person. Some or all of the following symptoms can occur including developmental delays and intellectual disabilities, nearsightedness (myopia), dislocation of the lens in the front of the eye, abnormal blood clotting, and brittle bones (osteoporosis). People with this condition are often tall and slender. There are two forms of Homocystinuria, CBS-Related: One form is Vitamin B6-responsive, which is usually milder, and the other is B6-nonresponsive. Treatment includes a low protein diet and vitamin supplementation, including vitamin B6 for people who have the B6-responsive type.

What causes Homocystinuria, CBS-Related?

Homocystinuria, CBS-Related is caused by a change, or mutation, in both copies of the CBS gene pair. These mutations cause the genes to not work properly or not work at all. The function of the CBS genes is to process the amino acid homocystine into cystathionine. When both copies of this gene pair do not work correctly, homocystine and other substances build up in the blood which leads to the symptoms described above.

Homocystinuria, Type cblE

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What is Homocystinuria, Type cblE?

Homocystinuria, Type cblE is an autosomal recessive disorder in which the body cannot use the vitamin B12 (cobalamin) correctly.  This leads to an abnormal buildup of the amino acid homocystine and other toxic substances in the blood.  Symptoms of Homocystinuria, Type cblE vary from person to person but usually begin within the first two years of life and can include small head and brain (microcephaly), lack of energy, feeding problems, developmental delay, intellectual disability, seizures, vision problems, poor muscle tone (hypotonia), and large red blood cells (megaloblastic anemia).  Some people with this condition have milder symptoms that start in the teen years or early adulthood and may include behavior and personality changes, hallucinations, mental illness, and decline in memory and skills. Treatment, which includes daily supplements and medication, helps to reduce the symptoms but cannot reverse any damage that has already occurred.

What causes Homocystinuria, Type cblE?

Homocystinuria, Type cblE is caused by a gene change, or mutation, in both copies of the MTRR gene pair.  These mutations cause the genes to not work properly or not work at all.  When both copies of this gene do not work correctly, homocystine builds up in the blood which leads to the symptoms described above.

Hydrolethalus Syndrome

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What is Hydrolethalus Syndrome?

Hydrolethalus Syndrome is an autosomal recessive disorder in which infants are born with extra fingers and toes, brain malformations, hydrocephalus (water on the brain), and heart defects.  During pregnancy there is often too much amniotic fluid, and preterm delivery is common.  Infants with Hydrolethalus Syndrome are usually stillborn or die during infancy.  There is no cure or treatment for this disorder.   

What causes Hydrolethalus Syndrome?

Hydrolethalus Syndrome is caused by a gene change, or mutation, in both copies of the HYLS1 gene pair. These mutations cause the genes to not work properly or not work at all. When both copies of this gene do not work correctly, it leads to the symptoms described above.

Hyperornithinemia-Hyperammonemia-Homocitrullinuria (HHH Syndrome)

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What is Hyperornithinemia-Hyperammonemia-Homocitrullinuria (HHH Syndrome)?

Hyperornithinemia-Hyperammonemia-Homocitrullinuria (HHH Syndrome), also called Ornithine Translocase Deficiency, is an autosomal recessive disorder that causes ammonia to build up in the blood. Ammonia is formed when proteins are broken down in the body and is toxic if the levels become too high. The age of onset and severity of symptoms vary from person to person.  Infants with the severe form of HHH Syndrome have episodes of low energy (lethargy), feeding problems, vomiting, seizures, and sometimes coma.  They often have problems controlling their breathing and body temperature and may have unusual body movements. Other symptoms of HHH Syndrome can include developmental delay, learning disabilities, muscle tension and stiffness (spasticity), and liver problems. Later-onset (childhood or adult) forms of HHH Syndrome are usually less severe and may include episodes of high blood ammonia after high-protein meals, during illness, or after long periods without food (fasting).  These episodes can include vomiting, lethargy, coordination and movement problems, confusion, headaches, and blurred vision. Treatment includes a medical low-protein diet along with special supplements and medications to lower the amount of ammonia in the blood.

What causes Hyperornithinemia-Hyperammonemia-Homocitrullinuria (HHH Syndrome)?

Hyperornithinemia-Hyperammonemia-Homocitrullinuria (HHH Syndrome) is caused by a change, or mutation, in both copies of the SLC25A15 gene pair.  These mutations cause the genes to not work properly or not work at all.  The SLC25A15 genes make an enzyme that helps the body break down nitrogen from food.  When both copies of the SLC25A15 gene do not work correctly, nitrogen builds up in the blood as ammonia, causing the symptoms described above. 

Hypohidrotic Ectodermal Dysplasia, X-Linked

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What is Hypohidrotic Ectodermal Dysplasia, X-Linked?

Hypohidrotic Ectodermal Dysplasia, X-Linked is an X-linked inherited disorder that causes sparse body hair, reduced ability to sweat, and the absence of teeth. People with Hypohidrotic Ectodermal Dysplasia, X-Linked need to keep cool during hot weather, may need special hair care products or wigs, and need to visit the dentist early in childhood.  Dentures or other dental restoration may be offered in childhood. Growth and development are otherwise normal. Girls tend to have fewer and milder symptoms of Hypohidrotic Ectodermal Dysplasia, X-Linked while boys show more features of the condition. 

What causes Hypohidrotic Ectodermal Dysplasia, X-Linked?

Hypohidrotic Ectodermal Dysplasia, X-Linked is caused by a change, or mutation, in the EDA gene.  This mutation causes the gene to not work properly or not work at all.  People with Hypohidrotic Ectodermal Dysplasia, X-Linked either have an absence of or a non-working form of a protein called ectodysplasin-A in their cells. When this protein is missing or does not work correctly it leads to the symptoms described above.

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