Medical Genetics Around the World Autosomal Recessive Disorders

2242JMed Genet 1994;31:224-233 Medical genetics around the world J Med Genet: first published as 10.1136/jmg.31.3.224 on 1 March 1994. Downloaded from Autosomal recessive disorders among Arabs: an overview from Kuwait Ahmad S Teebi Abstract which are the most common category of gen- Kuwait has a cosmopolitan population of etic disorders among Arabs in Kuwait. 1-7 million, mostly Arabs. This population is a mosaic of large and small minorities representing most Arab communities. In The country and population general, Kuwait's population is charac- Kuwait is a small Arab country situated in the terised by a rapid rate of growth, large north east of the Persian Gulf. It is bounded family size, high rates of consanguineous on the north and north east by Iraq and on the marriages within the Arab communities south by Saudi Arabia. The country's total with low frequency of intermarriage area (6880 square miles) is barren desert that is between them, and the presence of gen- rich in oil which is the source of Kuwaiti etic isolates and semi-isolates in some wealth. The population is cosmopolitan and extended families and Bedouin tribes. comprised of large and small minorities. Until Genetic services have been available in August 1990 (Iraqi invasion), its 1-7 million Kuwait for over a decade. During this people, according to a 1985 census,8 were made time it has become clear that Arabs have up of 40% Kuwaiti natives and Bedouin, and a high frequency of genetic disorders, 60% immigrants, the majority of whom were and in particular autosomal recessive Arabs. These immigrants were mostly from traits. Their pattern is unique and some Arabian Middle Eastern countries; however, disorders are relatively common. Ex- small minorities from North Africa are also amples are Bardet-Biedl and Meckel present. One of the large minorities before the syndromes, phenylketonuria, and fami- invasion of Kuwait were the Palestinians who lial Mediterranean fever. A relatively formed about 22% of the total population at http://jmg.bmj.com/ large number of new syndromes and var- that time. Those considered to be Kuwaiti iants have been delineated in Kuwait's natives are the early settlers of the urban population, many being the result of centres originating mostly from neighbouring homozygosity for autosomal recessive Arab countries, while the Bedouin are the genes that occurred because of inbreed- nomadic Arabs of the desert who live on the ing. Some of these syndromes have sub- fringes of the Arabian peninsula which in- sequently been found in other parts of the cludes parts of Kuwait, Saudi Arabia, Qatar, on September 24, 2021 by guest. Protected copyright. world, negating the concept ofthe private United Arab Emirates, Oman, Iraq, Jordan, syndrome. This paper provides an over- and Syria as well as Negev and Sinai desert. view of autosomal recessive disorders Over the past three to four decades, they have among the Arabs in Kuwait from a per- settled in urban centres and have acquired the sonal perspective and published studies, citizenship of the countries that host them. and highlights the need for genetic ser- Those who lived in Kuwait have acquired vices in Arab countries with the goal of Kuwaiti nationality and some of them became prevention and treatment of genetic dis- indistinguishable from natives. However, orders. Bedouins form tribal communities which are quite isolated. It is very likely that individual (J Med Genet 1994;31:224-233) people from the same tribe or kindred have settled in different Arab countries and In contrast to the genetically well studied acquired their nationalities. populations of North America and Europe, Also, the Kuwaiti population has one of the Department of particularly commnunities such as the Amish,' highest growth rates in the world (approxim- Genetics, Yale and com- 50000 live and University School of French Canadians,2 Jews,3 many ately births/year) large family Medicine, New Haven, munities within the Arab world remained size with five children being an average num- Connecticut, USA unstudied. However, previous efforts have ber of offspring per family.8 The rate of con- A S Teebi been made to study genetic disorders in some sanguineous marriage is high, with high Correspondence to Arabian countries such as Lebanon,4 Saudi inbreeding coefficients not only within the Dr Teebi, Division of I here a Medical Genetics, The Arabia,5 and Egypt.67 present geneti- Kuwaiti native population910 but also within Montreal Children's cist's experience in Kuwait and review per- other Arab communities, according to studies Hospital, 2300 Tupper, in order to an or in their Montreal, Quebec H3H 1P3, tinent published reports give conducted in Kuwaitl' countries of Canada. overview of autosomal recessive disorders, origin'116 (table 1). The most frequent form of Autosomal recessive disorders among Arabs: an overview from Kuwait 225 Table 1 Frequencies of consanguineous marriages among Arabs clinical, cytogenetic, and genetic counselling Population Frequency (%) Ref Comments services, to teach medical genetics to medical residents and other health professionals, and to Kuwaiti 54-3 9 Higher rates among Bedouin tribes J Med Genet: first published as 10.1136/jmg.31.3.224 on 1 March 1994. Downloaded from 37-8 10 conduct research directed towards under- Egyptian 23-3 10 Sample from Kuwait standing genetic problems in the community. 28-96 11 Higher rates in rural areas Iraqi 57-87 12 Higher rates in rural areas Genetic services have subsequently been Jordanian 36-2 10 Sample from Kuwait expanded to involve satellite clinics at the Al- 50-0 13 Lower rates among Christians Lebanese 26-0 14 Lower rates among Christians Amiri Hospital in Kuwait City and satellite Palestinian 39 0 15 Arabs in Israel community genetic programmes at three re- 38-7 16 Arab village in Israel gional hospitals in the governorates of Farwa- nia, Jahra, and Al-Ahmadi. Services in these consanguineous marriage is between first cou- regions were furnished on a weekly or twice sins, particularly paternal first cousins. Double weekly basis and on demand. The centre in first cousin marriages also exist. The fre- the years 1985 to 1990 was staffed by three quency of intermarriage between different trained geneticists at the consultant level, three Arab communities is low, which is also the case others at the registrar or senior registrar level, for some extended families and tribes within two nurses, and two social workers, and a the community. This has resulted in sustained reasonably equipped and staffed cytogenetics isolation particularly for the Bedouins and laboratory. some wealthy families. Genetic disorders in Kuwait Religion, culture, and genetic issues At birth, the incidence of major defects is Islam is the predominant religion among slightly higher than the 2 to 3% found in the Kuwaitis, the majority being Sunnite Muslims world's major surveys. However, if other dis- who are generally described as being modest orders that manifest later in life are included, with a strong faith in Islam. Despite the wes- the figure would be substantially higher than ternisation of a significant sector of the popula- in other parts of the world and the profile is tion, many still maintain their cultural ties and distinctive. In the virtual absence of prenatal religious principles. Although Islam, accord- diagnosis and termination of pregnancy, and ing to many religious scholars, discourages the long reproductive period, patients with consanguineous marriages, such marriages chromosomal anomalies, particularly trisomy have been traditionally practised over many 21, constitute approximately 28% of patients generations because of social, economic, and seen at the genetic clinic (unpublished data on geographical factors. Because they are forbid- 1300 new patients seen at the Al-Amiri satel- den by Islam, uncle-niece/aunt-nephew mar- lite clinic and Farwania community genetic riages are virtually non-existent.'7 Prenatal programme over a seven year period from 1983 diagnosis is acceptable for purposes of reassur- to 1990). Although the incidence of aneuploi- http://jmg.bmj.com/ ance or of therapy. Termination of pregnancy, dies among live births is higher than other however, at any stage is absolutely forbidden parts of the world,20 the pattern of chromoso- (haram), unless the mother's life is endan- mal abnormalities in general does not appear to gered.'8 Under Islamic law, according to some be significantly different. On the other hand, interpretations, termination of pregnancy is birth defects as a result of known teratogens considered a crime. 9 However, couples may form only 1 to 2% of patients, partly because avoid pregnancy if they are at an unacceptably ofrestricted use of drugs and chemicals, prohi- high risk of having a child with a certain bition of alcohol, and the fact that the vast on September 24, 2021 by guest. Protected copyright. genetic defect. On the other hand, artificial majority of females are naturally immune to insemination using the husband's sperm rubella before childbearing age. The remain- (AIH) and in vitro fertilisation (IVF) using the ing 70% of patients seen in genetic clinics can husband's sperm is acceptable, but using be divided as follows. (1) Known autosomal donor sperm is absolutely forbidden. In recessive (AR) disorders or unknown disorders general, assisted reproduction using the hus- with a family pattern suggestive of AR inherit- band's and wife's gametes is acceptable. Adop- ance (approximately 45%). (2) Known multi- tion has been practised since the early ages of factorial and polygenic disorders (18%). (3) Islam. However, "legal" adoption is not Known and unknown autosomal dominant allowed. disorders (12%). (4) Unknown disorders with- out suggestive family pattern (22%). (5) X linked disorders (2 to 3%). Genetic services In addition to data from the survey (personal Genetic services on a small scale began in observation), sources of information about AR Kuwait in the late 1 960s but were discontinued phenotypes include personal communications, in the early 1970s because of the lack of quali- published studies, and case reports (general fied personnel.

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