Genetic disorders are particularly significant in the Gulf Region and the Middle East because of intermarriage among close relatives, which is a risk factor for genetic disorders and birth defects. The prevalence of such genetic diseases in the Middle East and strategies for their treatment and prevention were among the topics of the second Qatar Genetics Symposium, held Oct. 31 at Weill Cornell Medical College in Qatar (WCMC-Q).

"This region of the world is largely inhabited by Arabs and Muslims who traditionally favor close-kin marriage," said Dr. Ahmed Teebi, professor of pediatrics and genetic medicine at WCMC-Q. "The consanguinity rates range from 20-70 percent in most Middle Eastern countries." In his presentation, Teebi discussed the large number of abnormalities that have been reported among people in Middle Eastern countries. He has published numerous papers on his discovery of more than 40 such genetic disorders and is involved in research projects focused on their discovery at the genetic level and clinical management.

According to Dr. Sheila Unger from the Institute of Human Genetics, the number of disorders with a known gene has grown exponentially. "As of last count, 372 different skeletal abnormalities were known, with 215 having a connection with 140 different genes," she said. Progress in genetic deciphering of skeletal disorders has provided valuable information about physiological mechanisms, she said, but international cooperation is necessary for real progress in fundamental clinical research.

Although consanguinity is associated with higher frequency of genetic disorders and birth defects, it also facilitates mapping genes, according to Dr. Hatem El-Shanti, director of the Shafallah Medical Genetics Center in Doha. "The identification of genes after mapping is a step forward for honing the diagnostic tools used for diagnostic testing and carrier identification," he said.

"The determination of the molecular development of neurological disorders is indispensable to the development of therapies for these disorders," said Dr. Mustafa A.M. Salih, professor of pediatric neurology in the College of Medicine at King Saud University in Saudi Arabia. "It also plays a vital role in genetic counseling and prevention of handicaps."

Expatriates make up about 80 percent of the 5 million inhabitants in the United Arab Emirates, but intermarriage among them is rare and consanguineous marriages are still the norm, according to Dr. Lihadh Al-Gazali, professor of pediatrics, United Arab Emirates University. "The UAE currently ranks sixth out of 193 countries in terms of prevalence of birth defects, mainly due to genetic causes," said Al-Gazali, who also discussed the clinical and molecular basis of several disorders identified in the UAE population.

"Rare skeletal disorders provide the opportunity to understand genes and pathways that regulate the development of cartilage and bone," said Muhammad Faiyaz-Ul-Haque, Ph.D., scientific director of the Molecular Pathology Core Facility at King Faisal Specialist Hospital and Research Center in Saudi Arabia. "The advances in describing the genetic defect in several conditions has endowed us with insight into the genes controlling normal growth of cartilage and development of bone. It has also open new diagnostic perspectives."

The symposium was sponsored by Hamad Medical Corp. and WCMC-Q.