What Are the Disorders?

The following are descriptions of the 11 most common diseases, in order of carrier frequency, courtesy of Genzyme.  Click here for a printable brochure in Adobe Acrobat (PDF) format.

Type 1 Gaucher disease² - Carrier frequency: 1 in 15

Gaucher disease is an inherited disorder in which a fatty substance builds up in the body, especially in the spleen, liver, and bone marrow, and secondarily in the lungs, kidneys, and intestines.  Children or adults may have bruising, fatigue, anemia, nosebleeds, fractures, and enlargement of the liver and spleen.  Treatment options are available for Type 1 Gaucher disease.

Cystic Fibrosis (CF)³ - Carrier frequency: 1 in 26

CF is a disorder of unusually thick, sticky mucus production, primarily affecting the lungs and digestive system.  Most individuals with CF require lifelong medical care and experience reduced life expectancy.

Tay-Sachs disease⁴ - Carrier frequency: 1 in 30

Tay-Sachs disease is the best-known Jewish genetic disorder and is caused by a deficiency of an enzyme called hexosaminidase A (or hex A).  Lack of this enzyme affects the brain and the nervous system, causing rapid and progressive deterioration, with death usually occurring by the age of 6.  Babies with Tay-Sachs disease being to lose developmental skills at 3 to 6 months of age. 

Familial Dysautonomia (FD)⁵ - Carrier frequency: 1 in 30

FD is a nervous system disorder that commonly includes pain insensitivity, vomiting and sweating episodes, inability to produce overflow of tears, and unstable blood pressure or temperature.  Intelligence is often normal, but learning disabilities are common.  Symptom management improves quality of life, but only 50% will reach 30 years of age.

Canavan disease⁶ - Carrier frequency: 1 in 57

Canavan disease is a rare and devastating childhood nervous system disorder.  Canavan affects the formation of myelin, or white matter of the brain.  Symptoms usually occur within the first few months of life and the disease is fatal in early childhood.

Glycogen Storage Disorder Type 1a (GSD 1a)⁷ - Carrier frequency: 1 in 71*

GSD 1a is a disorder that, if untreated, results in severely low blood sugar, enlarged liver, growth retardation, and bleeding disorders.  Treatment consists of strict diet and continuous tube feeding of glucose (sugar).

Maple Syrup Urine disease (MSUD)⁸ - Carrier frequency: 1 in 81

MSUD is a disorder that leads to the buildup of branched-chain amino acids in the blood.  Without treatment, classic MSUD results in mental retardation, physical disabilities, coma, and death.  Treatment requires dietary restriction of branched-chain amino acids through a special medical formula and intensive monitoring.

Fanconi Anemia Type C⁹ - Carrier frequency: 1 in 89

An inherited anemia sometimes accompanied by short stature, skeletal defects, and skin abnormalities.  Learning disabilities or mental retardation sometimes occur.  The risk of early childhood cancer, especially leukemia, is increased.  There is currently no treatment.

Niemann-Pick disease Type A¹⁰ - Carrier frequency: 1 in 90

Niemann-Pick disease type A is a severe brain and spinal cord disorder in infants.  Affected babies experience feeding difficulty, recurrent vomiting, and enlargement of the spleen and liver, which causes the abdomen to appear distended by 6 months of age.  There is currently no treatment, and death occurs by 4 years of age.

Bloom's Syndrome¹¹ - Carrier frequency: 1 in 100

Bloom's Syndrome is a disorder characterized by poor growth, sun sensitivity, and high susceptibility to cancer.  Death from cancer usually occurs before 30 years of age.  Intelligence is normal.  There is currently no treatment.

Mucolipidosis Type IV (ML4)³ - Carrier frequency: 1 in 122 

ML4 is a disorder characterized by severe neurological and eye abnormalities.  It usually appears within the first year of life and affected individuals reach the development age of 1 to 2 years.  There is currently no treatment.

*Population of GSD 1a mutation frequency is currently under evaluation.  However, published data indicate a frequency of 1 in 71 for individuals of Ashkenazi Jewish descent.

References:  2. Kronn D. Jansen V. Ostrer H. Carrier screening for cystic fibrosis, Gaucher disease, and Tay-Sachs disease in the Ashkenazi Jewish population. Arch Intern Med. 1998;158:777-781.  3. Genetic disease details. Fairfax Cryobank website. http://www.fairfaxcryobank.com/geneticdiseasedetails.aspx. Accessed July 7, 2008.  4. Ashkenazi disorders: Mendelian. Tay-Sachs disease. Chicago Center for Jewish Genetic Disorders website. http://www.jewishgeneticscenter.org/what/ashkenazi/tay.asp. Accessed July 7, 2008.  5. Ashkenazi disorders: Mendelian. Familial dysautonomia. Chicago Center for Jewish Genetic Disorders website. http://www.jewishgeneticscenter.org/what/ashkenazi/familial.asp. Accessed July 7, 2008.  6. Feigenbaum A, Moore R, Clarke J, et al. Canavan disease: carrier-frequency determination in the Ashkenazi Jewish population and development of a novel molecular diagnostic assay. Am J Med Genet. 2004;124A:142-147.  7. Ekstein J, Rubin BY, Anderson SL, et al. Mutation frequencies for glycogen storage disease la in the Ashkenazi Jewish population. Am J Med Genet. 2004;129A:162-164.  8. Maple syrup urine disease. Jewish Genetic Diseases Center of Greater Phoenix website. http://www.jewishgeneticsphx.org/maple.html. Accessed July 1, 2008.  9.  Fanconi anemia, type C. Jewish Genetic Diseases Center of Greater Phoenix website. http://www.jewishgeneticsphx.org/fa.html. Accessed July 1, 2008.  10. Niemann-Pick disease. Albert Einstein Healthcare Network website. http://www.einstein.edu/yourhealth/genetic/jewishgenetic/article8416.html. Accessed July 1, 2008.  11. Vallance H, Ford J. Carrier testing for autosomal-recessive disorders. Crit Rev Clin Lab Sci.2003;40(4):473-497.