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The last Ashkenazi Jewish genetic condition left for me to cover, aside from Cystic Fibrosis which has high carrier rates for all people with Caucasian ancestry (1/25), is Niemann-Pick disease. There are five subtypes of Niemann-Pick disease, though only Type A is more frequent in Ashkenazi Jewish populations.

• Niemann-Pick disease Type A is a neurodegenerative disorder that causes babies to experience feeding difficulty, recurrent vomiting, and enlargement of the spleen and liver. Like Tay-Sachs disease, a child’s decline can be rapid and death usually occurs by 3-5 years of age, due to infections such as pneumonia.
• 1 in 80 Ashkenazi Jews are carriers of Niemann-Pick Type A.
• Genetic testing can tell whether you are an unaffected carrier of Fanconi anemia. Testing detects 99% of carriers for Niemann-Pick Type A.
• Niemann-Pick Type A is inherited in an autosomal recessive fashion, which means that in order for a child to be affected, he or she must inherit two copies of the gene change — one from each parent. If your partner is also a carrier, you have a 1 in 4 chance of having a child with Niemann-Pick Type A disease.
• National Niemann-Pick Disease Foundation
• Other Ashkenazi Jewish genetic conditions
• DNA Direct’s FAQs on Ashkenazi Jewish genetic testing
  

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A while back, I began a series of short posts on genetic conditions that are most common in people with Ashkenazi Jewish heritage. Now it’s time to pick those back up again. Where were we? Fanconi Anemia.

Fanconi Anemia is a blood disorder characterized by deficiency of red blood cells, white blood cells and platelets. Fanconi Anemia (Type C) causes developmental delay, increased risk of cancer, and congenital birth defects.

• 1 in 89 people of Jewish ancestry are carriers of the gene alteration that causes Fanconi anemia.
• Some children with Fanconi anemia have been successfully treated with bone marrow transplantation, but this treatment is still experimental.
• There are five subtypes of Fanconi anemia. Only Type C occurs with increased frequency among people with Ashkenazi Jewish ancestry. (more…)

Mucolipidosis IV (ML4) is a neurodegenerative disorder characterized by growth and developmental delays, progressive retinal degeneration, and crossed eyes. It has relatively high carrier rates in the Ashenazi Jewish community.

• Most infants affected with ML4 develop symptoms within their first year of life, and most never speak, walk, or develop beyond the level of a 1–2 year old. Most people with ML4 usually live into adulthood.
• About 1 in 100 to 1 in 127 people of Ashkenazi Jewish descent are ML4 carriers, which means they have one copy of the gene change that causes Mucolipidosis Type IV.
• When two carriers have a child together, there is a 1 in 4 chance the child will have ML4. (See autosomal recessive inheritance)
• Highly accurate carrier testing and prenatal diagnosis is available for ML4, both for families with a previous history of the disease and for all couples with Ashkenazi Jewish ancestry.
• ML4 Resources: National MPS Society, Inc., ML4 Foundation

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Canavan disease is one of the most common Ashkenazi Jewish genetic conditions. 1 in 40 Ashkenazi Jews are carriers of Canavan disease. As a result of this high carrier rate and the seriousness of the condition, the American College of Medical Genetics and the American College of Obstetrics and Gynecology recommend Canavan carrier screening for all Ashkenazi Jewish individuals before pregnancy. (Here’s the ACMG statement)

• Canavan disease characterized by developmental delay, a large size head, seizures, blindness, and gastrointestinal problems.
• Genetic testing is available to determine if a person is a carrier of Canavan disease. Testing can identify about 97% of Ashkenazi Jewish carriers.
• When two carriers have a child together, there is a 1 in 4 chance the child will have Canavan. (See autosomal recessive inheritance)
• 1 in 5,000 Jews have Canavan disease. (With carrier screening, it’s likely that this number is shrinking.)
• Canavan disease is caused by a deficiency of an enzyme, aspartoacylase. This enzyme is necessary for the maintenance of the myelin sheaths of nerve cells. Deficiency in the enzyme causes progressive degeneration of the central nervous system.
• No treatment is currently available for Canavan disease.
• Resources for Canavan disease: The Canavan Foundation, The Canavan Research Foundation, The United Leukodystrophy Foundation
• More posts about Ashkenazi Jewish genetic conditions

Technorati Tags: canavan disease, ashkenazi jewish diseases, carrier testing, genetic testing, genes, inheritance patterns, symptoms, treatment, resources

Familial Dysautonomia, also called FD, is a neurologic disorder characterized by episodic vomiting, abnormal sweating, pain and temperature insensitivity, an inability to produce tears, scoliosis, and abnormal feeding and sucking difficulties. This disease is found almost exclusively in Ashkenazi Jewish families.

• 1 in every 36 Ashkenazi Jews is a carrier of FD – and the disease is almost exclusively found in Ashkenazi Jewish families.
• When two carriers have a child together, there is a 1 in 4 chance the child will have Familial Dysautonomia. (See autosomal recessive inheritance)
• Genetic testing, also called “carrier screening”, is available to determine if you are a carrier of FD. This test has a detection rate of 99%.
• A single mutation on the IKBKAP gene on chromosome 9 accounts for most cases of FD.
• The only treatments available for FD treat the symptoms of the disease. Though the treatments cannot cure FD, they can improve the length and quality of a patient’s life.
• Resources for families with FD: FD Hope, National Dysautonomia Research Foundation, Dysautonomia Treatment and Evaluation Center, Dysautonomia Foundation, Inc.
• Why certain genetic conditions are found almost exclusively in certain ethnic groups: the “founder effect” and “beneficial mutation” theory.
• More posts about Ashkenazi Jewish genetic conditions

Technorati Tags: familial dysautonomia, ashkenazi jewish diseases, carrier testing, genetic testing, genes, inheritance patterns, symptoms, treatment, resources

I’ve posted recently on Ashkenazi Jewish genetic diseases. Here’s one you don’t hear about that often: Bloom Syndrome. It’s is a condition that, although very rare in the general population, has much higher carrier rates among Ashkenazi Jews. What is Bloom Syndrome?

• One in 100 Ashkenazi Jews are unaffected carriers – they carry one copy of the gene change that causes Bloom Syndrome. When two carriers have a child together, there is a 1 in 4 chance the child will have Bloom Syndrome. (See autosomal recessive inheritance)
• People with Bloom Syndrome have characteristic appearances that include a long, narrow face, prominent nose and ears, and a smaller-than-average stature. The also have a tendency to develop patches of reddened skin on the face.
• (more…)

The News section of today’s JAMA reports on exciting new research that may lead to more effective treatment of Gaucher disease. (How odd that I just posted on this rarely discussed condition yesterday.)

Researchers have discovered new details about the protein that is mutated in Gaucher disease. This protein, an enzyme called acid beta-glucosidase, is needed for the body’s cells to stay healthy. People with Gaucher disease produce an inactive form of the enzyme and as a result, cannot process a particular lipid. This results in liver dysfunction and the other symptoms of Gaucher disease.

This new research has uncovered a small molecule, called isofagomine, that can bind to the enzyme, changing its shape into that of an active enzyme.

Technorati Tags: gaucher disease, research, treatment, causes, ashkenazi jewish, genetics

Here are fast facts about Gaucher Disease, the most common genetic condition in Ashkenazi Jewish people.

• 1 in every 18 Ashkenazi Jews is a carrier for Gaucher disease.
• Carriers are unaffected, but when two carrier have a child, they have a 1 in 4 (25%) chance of having a child with Gaucher disease.
• Gaucher disease mainly affects the spleen, liver, and bones, and occasionally the lungs, kidneys, and brain. This disease can range in severity from mild to chronic.
• Symptoms of Gaucher disease can develop at any age, but they frequently begin during adolescence and early adulthood.
• The most common symptom is chronic fatigue caused by anemia. People may experience easy bruising, nosebleeds, bleeding gums, and prolonged and heavy bleeding with menstruation and after childbirth. (more…)

Last fall I posted on Ashkenazi Jewish genetic diseases, a number of inherited diseases that occur primarily in people of AJ descent (as a result of the “founder effect“). AJ diseases are commonly known about within the AJ community, but many non-Jewish people are completely unaware of them.

As a result of carrier screening (the ability to test parents-to-be to see if they carry a mutation for the conditions), the actual rates of individuals affected with these disease is dropping. That’s the good news. That people who are appropriate for testing don’t know about testing is the bad news. (My rant on that will have to wait until next week, when the Week of Science challenge has ended)

So here’s the skinny on how these disease are inherited, why people are “silent” carriers, and why carrier testing works:

(more…)

In an earlier post, I talked about Ashkenazi Jewish diseases in general. Now let’s turn to one disease in particular, Tay-Sachs, which is a disease that sadly claims the lives of children under the age of 5.

Tay-Sachs more frequently arises in children with Ashkenazi Jewish ancestry because of the increased likelihood of people in this population to be carriers. Within the general population, only 1 in 300 people are carriers of Tay-Sachs disease, while within the Ashkenazi Jewish population, 1 in 30 people are carriers.

Though it is not curable, Tay-Sachs is preventable through carrier testing when a couple is planning a pregnancy. (more…)

Almost every ethnic or demographic group has higher rates of certain genetic diseases than the general population. There are a number of genetic conditions that are relatively unknown, but terribly debilitating – and all occur most frequently in people with Ashkenazi Jewish ancestry:

• Bloom’s Syndrome
• Canavan Disease
• Familial Dysautonomia
• Fanconia Anemia
• Gaucher Disease
• Mucolipidosis IV
• Niemann-Pick Disease
• Torsion Dystonia
• Tay-Sachs Disease

How is it possible that certain diseases are more common within the Ashkenazi Jewish population? (more…)

Why be aware of cystic fibrosis? As many as 1 in 25 people in the US is a CF carrier. And that’s a pretty high carrier rate for a condition that most people don’t know about.

Cystic fibrosis, or CF, is an inherited disease that affects the lungs, digestive system, sweat glands, and male fertility. If you are pregnant - or thinging about getting pregnant - you should know about CF.

You might be suprised to know:

• A simple genetic test can help you find out if you are a carrier. If you are, you can figure out your chances of passing on that CF mutation to a child. If your partner is also a carrier, you have a 1 in 4 chance of having a child with CF.
• CF occurs in all ethnic groups, but people with European or Ashkenazi Jewish ancestry are more likely to be carriers than others.
• CF mutations can be passed down “silently” for many generations, without anyone in the family ever having CF.
• This is why medical guidelines say that everyone who is pregnant or planning a pregnancy — and everyone with Caucasian ancestry — should be offered CF carrier screening.
• In rare instances, people with frequent lung infections or chronic sinusitis are diagnosed late in adulthood as having CF. (Most people don’t hear about “mild” CF.)
• There are over a 1000 known CF mutations, and scientists are learning more about what they mean every day. Treatments are continually in development, and people with CF are living longer and healthier lives than before.

Want to learn more or spread the word about CF? The Cystic Fibrosis Foundation is a great resource that has been providing information, support and advocacy for 51 years. (Here are more resources.) Looking for support? The Lawrences are a family blogging about their experiences of raising their children, including a daughter with CF.

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