8 October 2009
Arab nations have some of the highest rates of genetic disorders in the world, according to the Centre for Arab Genomic Studies (CAGS). More than 900 different genetic diseases have been identified, around 200 of them prevalent only within the Gulf Cooperation Council states (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates). The figures appear to include diabetes and breast cancer; it is worth noting that the majority of cases of these conditions arise from a combination of environmental and genetic factors and are not technically ‘genetic diseases’, although genetic susceptibility to such conditions can be significant. There are additionally sub-groups of these diseases that are effectively inherited as single-gene (monogenic) disorders.
The high prevalence of genetic disorders is due in part to the relatively high levels the result of consanguineous marriages (i.e. marriage between close relatives such as first cousins) in this region; in parts of the United Arab Emirates more than 50% of marriages are between relatives, for example. Other factors also have an effect; for example, social trends to continue childbearing up until the menopause can increase rates of chromosomal disorders [see Nat Genet. 2006 38(8):851].
Information about the rates of genetic disease is from an ongoing CAGS project, the Catalogue for Transmission Genetics in Arabs (see previous news), a database for recording and identifying genetic disorders within the Arab world. The purpose of the CTGA database, which is continuously expanding with the recognition of new conditions, is to help plan regional health policies for treatment and prevention. According to CAGS assistant director Dr Ghazi Tadmouri, the aim is to give a “bird’s- eye view of each country on genetic diseases” (see The National news article). He noted that most of these conditions were single-gene disorders, for which screening (to aid early diagnosis, treatment and prevention) is relatively easy, but added that there was still generally poor monitoring of genetic diseases in most Arab countries, along with inadequate facilities for screening and prenatal diagnosis.