A number of genetic disorders occur more frequently in certain ethnic populations. In the Ashkenazi Jewish population (those of Eastern European descent), it has been estimated that one in four individuals is a carrier of one of several genetic conditions. These diseases include Tay-Sachs Disease, Canavan, Niemann-Pick, Gaucher, Familial Dysautonomia, Bloom Syndrome, Fanconi anemia, Cystic Fibrosis and Mucolipidosis IV.
Recent research also indicates Crohns disease, Ulcertative Colitis, and a mutation which increases the chance of developing Parkinson’s disease are all more commonly found in Ashkenazi Jews. Bloom Syndrome Bloom Syndrome hinders normal growth. Children typically reach a maximum of five feet at maturity. Other symptoms include increased respiratory and ear infections, redness of the face, infertility in males and an increased risk of cancer.
Tay-Sachs Disease
A condition where children develop normally until about four to six months of age. It is at this time that the central nervous system begins to degenerate. Individuals with Tay-Sachs Disease lack an enzyme called hexosaminidase (Hex A). The child loses all motor skills and becomes blind, deaf and unresponsive. Death usually occurs by the age of four. The carrier rate in the Ashkenazi Jewish population is approximately 1 in 25. More rare than the infantile type is Late Onset Tay-Sachs Disease, where the progression of symptoms is slower and milder.
Canavan Disease
Very similar to Tay-Sachs Disease, with normal development until age two to four months, followed by progressive loss of previously attained skills. Most individuals with Canavan Disease die by the age of five. An estimated 1 in 40 Ashkenazi Jews is a carrier for this disease.
Niemann-Pick Disease – Type A
A disease in which a harmful amount of a fatty substance accumulates in different parts of the body. Failure to thrive and a progressive neurodegenerative course lead to death by three years of age. The carrier rate in the Ashkenazi Jewish population is approximately 1 in 90.
Gaucher Disease – Type 1
(Pronounced go-shay) is a variable condition, both in age of onset and in progression of symptoms. A painful, enlarged and overactive spleen, with anemia and low white blood cell count are usually the initial features of Gaucher Disease. Bone deterioration is a major cause of discomfort and disability. Approximately 1 in 14 Ashkenazi Jews is a carrier of this condition. Treatment is available.
Familial Dysautonomia
A disease that causes the autonomic and sensory nervous systems to malfunction. This affects the regulation of body temperature, blood pressure, stress response, normal swallowing and digestion. An estimated 1 in 30 Ashkenazi Jews is a carrier of FD.
Bloom Syndrome
Characterized by short stature, sun-sensitive facial skin lesions, an increased susceptibility to infections and a higher incidence of leukemia and certain cancers. The carrier rate is about 1 in 100 in the Ashkenazi Jewish population.
Fanconi anemia – Type C
A disease associated with short stature, bone marrow failure and a predisposition to leukemia and other cancers. Some children may have learning difficulties or mental retardation. Approximately 1 in 89 Ashkenazi Jews is a carrier for this condition.
Mucolipidosis IV
Caused by the accumulation of certain harmful substances throughout the body. Individuals with ML IV experience a range of levels of motor and mental retardation, with developmental delays often manifesting themselves as early as the first year of life. Other symptoms can be related to the eyes, such as corneal clouding, pseudostrabismus and retinal degeneration.
Cystic Fibrosis
A multi-system disorder that causes the body to produce a thick mucus. The mucus accumulates primarily in the lungs and the digestive tract, resulting in chronic lung infections and poor growth. CF does not affect intelligence. The carrier rate for CF among all Caucasian individuals is approximately 1 in 25. The CF carrier test has a detection rate of 97% in the Ashkenazi Jewish population.
Sephardi Genetic Diseases
Sephardi Jews, whose ancestry can be traced to North African and Mediterranean countries, including Spain and Greece, suffer from the same genetic diseases as other populations in these countries. Jews of Sephardi ancestry also have their own set of distinct carrier screening tests based on their country of origin.
Beta-Thalassemia
This disorder reducing the amount of hemoglobin can result in severe anemia in the first two years of life or in a milder case later in life. Roughly one in 30 people of Mediterranean descent carries the gene; one in 3,600 develops it.
Familial Mediterranean Fever
As many as one in 200 North African and Iraqi Jews, Armenians and Turks has the disease, distinguished by 12 to 72-hour bouts of fever. Symptoms usually start between ages five and 15.
Glucose-6-PhosphateDehydrogenase Deficiency (G6PD)
This common human enzyme deficiency affects an estimated 400 million people worldwide, and is transmitted from a carrier mother to her male infant. The disease can manifest itself as life-long hemolytic anemia or bouts of it. Some experience no symptoms at all, although certain oxidative drugs and infections as well as fava beans can induce it.
Glycogen Storage Disease, Type III (Cori’s Disease or Forbes Disease)
This disease prevents the liver and muscle from breaking down stored glycogen to glucose. Some develop hypoglycemia, an enlarged liver and weak muscles. Roughly one in 5,400 North African Jews has the disease.
Other diseases of connection to Sephardi origin include: Alpha-Thalassemia, Ataxia Telangiectasia, Corticosterone Methyloxidase Type II Deficiency, Costeff Optical Atrophy, Cystic Fibrosis (CF), Familial Creutzfeldt-Jakob Disease, Familial Tumoral Calcinosis (Normophosphatemic Type), Inclusion Body Myophy Type 2B, Metachromic Leukodystrophy, Polyglandular Deficiency Syndrome, Pseudocholinesterase Deficiency, Spinal Muscular Athrophy (SMA) and Wolman Disease.
