Sephardic Genetic Diseases

AUTOSOMAL RECESSIVE DISORDERS

Sephardic 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.  The diseases are not as serious as Ashkenazi Jewish genetic diseases, but can cause significant health problems. The disorders in the Sephardic population also vary with your country of origin.

Beta-Thalassemia

Beta-Thalassemia is an inherited blood disorder that reduces the production of the beta subunit of hemoglobin  and results in anemia.  Thalassemia major, the most severe form, results from severe mutations on both beta globin genes. It also is called Cooley’s anemia. Most affected children appear healthy at birth but they develop severe anemia and a large liver and usually need medical attention within the first two years of life . They grow slowly and often develop jaundice. Treatment is with regular transfusions and chelation therapy to prevent iron overload.  Carriers of one mutated thalassemia gene have Thalassemia minor which  is usually asymptomatic, though some have mild anemia.   The less severe form, thalassemia intermedia presents later with milder anemia that sometimes requires transfusion. Thalassemia intermedia results from milder abnormalities in both beta globin genes. Beta thalassemia is reported most commonly in Mediterranean, African, and Southeast Asian populations.   Roughly one in 30 people of Mediterranean descent carry the gene.

Familial Mediterranean Fever

Familial Mediterranean Fever is an inherited condition characterized by recurrent episodes of painful inflammation in the abdomen, chest, or joints. These episodes are often accompanied by fever and sometimes a rash. The symptoms and severity vary among affected individuals, sometimes even among members of the same family.  Typically, episodes last 12 to 72 hours. The length of time between attacks is also variable. The first episode usually occurs in childhood or the teenage years.  The carrier rate for FMF has been calculated to be as high as 1:3-1:7 in North African Jews, Iraqi Jews, Armenians, and Turks.

Glucose-6-Phosphate Dehydrogenase Deficiency (G6PD)

This common human enzyme deficiency affects an estimated 400 million people worldwide. It confers protection against malaria, which probably accounts for its high gene frequency. G6PD deficiency is passed along in genes from one or both parents to a child. The gene responsible for this deficiency is on the X chromosome. People of Mediterranean heritage, including Italians, Greeks, Arabs, and Sephardic Jews, also are commonly affected. People with G6PD deficiency lack enough of the enzyme G6PD, which helps red blood cells function normally. This deficiency can cause hemolytic anemia, usually after exposure to certain medications, foods, or even infections.  Most people with G6PD deficiency have no symptoms, while others develop symptoms of anemia only after red blood cells have been destroyed, a condition called hemolysis. In these cases, the symptoms disappear once the cause, or trigger, is removed. In rare cases, G6PD deficiency leads to chronic anemia. With the right precautions, a child with G6PD deficiency can lead a healthy and active life.   Some substances can be harmful to people with this condition when consumed—or even touched—such as fava beans and naphthalene (a chemical found in mothballs and moth crystals) and should be avoided.

Glycogen Storage Disease, Type III (Cori’s Disease or Forbes Disease)

GSD III is a very variable disorder characterized by the storage of structurally abnormal glycogen, termed limit dextrin, in both skeletal and cardiac muscle and/or liver. Glycogen is one of the primary fuel reserves for the body’s energy needs. During infancy and early childhood, patients with GSD III may have liver enlargement, low blood sugar and poor growth similar to those in GSD 1a. Hypoglycemia is rare in newborns with GSD III, but often manifests at age 3-4 months when many parents reduce feeding frequency. Muscular involvement usually is minimal during  childhood but often becomes the major feature by young adulthood. Carrier rate is 1:37 in the Sephardic Jewish individuals of North African descent. Disease management involves lifelong diet modification to keep the blood sugar from dropping.

—Adele Schneider, MD, FACMG
Medical Director, Victor Center for Jewish Genetic Diseases
Philadelphia, PA

Source: moment / Jewish Health

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