15 August 2009

Los Angeles: Persian Jewish genetics study

Cedars-Sinai Hospital in Los Angeles is conducting a screening program of the area's large Persian Jewish community for four disorders prevalent in that community. Three are easy to treat (if one knows about it), while the fourth is incurable.

The Los Angeles Times carried the story here.

Sean Delshad, 19, probably could have found more enjoyable things to do on a breezy Sunday afternoon. But instead he was waiting his turn at Sinai Temple -- along with dozens of other members of Los Angeles' large Persian Jewish community -- to undergo genetic testing.

The UCLA student deposited a few drops of saliva in a tube handed to him by a doctor and, in four to six weeks, he'll learn whether he carries gene mutations for four disorders that are especially prevalent among Persian Jews. Three are easy to treat -- provided a person knows he or she is afflicted. The fourth is incurable.

The screening program, conducted by the Cedars-Sinai Medical Genetics Institute, is a unique attempt to make broad-scale genetic testing more efficient by targeting ethnicity, a concept called ethnogenetics. Organizers hope to test at least 10,000 of the 30,000 Persian Jews in Southern California.

"The bottom line is, it's good to know. You can see what steps you need to take to be better prepared," Delshad said.
The institute's director, Dr. David L. Rimoin, was a Tay-Sachs genetic screening pioneer some four decades ago. Community-wide Tay-Sachs testing has reduced the incidence of that tragic disorder by some 90%.

Human genome mapping has revealed mutations in certain ethnic groups. According to Rimoin, every ethnic and racial group has five to 10 gene mutations that increase risk for specific conditions. Persian Jews have a strong tradition of cousin marriage, making the incidence of these traits more common.

For Persian Jews, this tradition began in 586 BC, during an era of captivity in Babylon, which is now Iran. For centuries, Persian Jews were isolated from other Jewish and non-Jewish communities by geography and reproductive practices. In the late 1970s, many migrated to the United States.
The LA Times story also addresses Cajun Tay-Sachs incidence, African American sickle cell anemia, Vietnamese thalassemia, Finnish congential nephrosis and Northern European cystic fibrosis.

The Persian Jewish program also tests for hereditary inclusion body myopathy, a condition that causes progressive weakness of the arms and legs with devastating results. The story discusses carriers and how they can avoid passing this on. One in 20 Persian Jews is a carrier.

Nahid Talassazan, 50, attended the screening because of the incidence of hereditary inclusion body myopathy in her family. One of her uncles married a cousin, and three of the couple's four children -- Talassazan's cousins -- have the disorder. "These things are worrisome," she says. "But I am very pro-science. I'd rather know than not know."
The other conditions associated with Persian Jewish heritage are:

* Pseudocholinesterase deficiency, which causes a sensitivity to anesthesia. Persian Jewish carrier incidence: One in 10.

* Congenital hypoaldosteronism, which makes the body lose salt and can result in dehydration, shock, short stature, blood pressure problems and salt craving. Persian Jewish carrier incidence: One in 30.

* Polyglandular deficiency, in which the body is deficient in multiple hormones. Persian Jewish carrier incidence: One in 50.

All four conditions are autosomal recessive disorders - both parents must carry the mutation for a child to inherit the disorder. Children of parents who both carry a gene for such recessive traits have a 25% chance of inheriting the disorder, a 25% chance of not carrying the gene mutation and a 50% chance of carrying one copy of the mutation.

About 100 people attended the Aug. 3 event and organizers were happy. The concern was that the community might fear testing results or fear stigmatization by it.

Organizers say that widespread community screening can lead to a dramatic decrease of these conditions in the Persian Jewish community, much like Tay-Sachs in the Ashkenazi community.

Screening is confidential. Individuals receive an identification bar code. Results are mailed to the participant's home with information on how to follow up with a doctor or genetic counselor.

Rimoin hopes the program for Persian Jews will be expanded to New York, with a significant Persian Jewish community, and to Israel.

The first 1,000 tests will be administered free. Later tests will cost $200-300. The next screening will take place August 27 at Cedars-Sinai Medical Center.

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