UAE) Population J Med Genet: First Published As 10.1136/Jmg.32.1.7 on 1 January 1995
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JMed Genet 1995;32:7-13 7 The profile of major congenital abnormalities in the United Arab Emirates (UAE) population J Med Genet: first published as 10.1136/jmg.32.1.7 on 1 January 1995. Downloaded from L I Al-Gazali, A H Dawodu, K Sabarinathan, M Varghese of different congenital abnormalities vary from Abstract one country to another depending on geo- The aim of this study was to establish the graphical, ethnic, and socioeconomic char- profile ofmajor congenital malformations acteristics of the population studied. Such in the United Arab Emirates (UAE) popu- studies are useful for planning health care, lation which has a high rate of con- including preventive programmes and edu- sanguinity. All births with birth weight cational and rehabilitation needs of the popu- above 500 g in the three hospitals in the Al lation. Recent advances in the diganosis of Ain Medical District of UAE were pro- congenital abnormalities has led to the iden- spectively studied from January 1992 to tification of many more dysmorphic syn- January 1994. About 98% of the births in dromes. In addition, the improvement in the district occur in these three hospitals. prenatal diagnostic techniques has led to an Detailed family history and clinical and increase in the number of congenital ab- relevant laboratory investigations were re- normalities which can be prevented.' corded in each case. Necropsy was not The population of the United Arab Emirates permitted. The major malformations were (UAE) is a mixture of different ethnic groups. classified as multiple or isolated single sys- The majority are Arab Muslims with a con- tem abnormalities as well as genetic or sanguinity rate of 54%; 30% of marriages are non-genetic disorders. Ofthe 16 419 births first cousin marriages.' These consanguinity which occurred during the two year figures were independently reproduced in a period, 173 (10.5/1000 births) had major pilot study from Al Ain Medical District (Al- malformations, 90 (52%) had multiple Gazali, unpublished data). Currently, there are malformations, and 83 (47-97%) had in- no preventive programmes for congenital ab- volvement ofa single system. Ofthe infants normalities and many women continue to re- with multiple malformations, 43 had re- produce after the age of 40 years. Attempting cognised syndromes, most of which are to provide genetic counselling for families of autosomal recessive disorders with a high children with congenital malformations in this frequency ofrare syndromes. Twenty eight population has highlighted several issues. (31%) had chromosomal abnormalities. These included a lack of accurate information http://jmg.bmj.com/ The most common systems involved in on the genetic and non-genetic causes of mal- infants with isolated single system mal- formation, and a lack of awareness by both formations include gastrointestinal (33), families and the health authorities of the central nervous system (17), and cardio- importance of genetic counselling in the pre- vascular (10). While the consanguinity rate vention of congenital malformations. was similar (57% v 54%), the frequency of The aim of this was to first cousin marriages was much higher study establish the incidence and pattern of congenital ab- on September 26, 2021 by guest. Protected copyright. (51% v 30%) in the study group compared normalities in the UAE population, as well as with the figures for the general population. the proportion of anomalies in which genetic The consanguinity rate was highest among factors are the syndrome cases, and related parents implicated, in order to identify the were more likely to have infants with mul- appropriate strategies for prevention. Department of Paediatrics, Faculty of tiple malformations than an isolated single Medicine and Health system abnormality with a relative risk of Materials and Sciences, UAE 1*69 (95% CL 1.27-2-24). Genetic factors methods University, PO Box could be A study of 16 419 consecutive live and still- 17666, Al Ain, United implicated in 116 (67%) ofthe 173 births over 500 g birth weight at the three main Arab Emirates cases ofmajor malformations and 49 (28%) in Al L I Al-Gazali were potentially preventable. The study hospitals Ain, UAE was carried out over A H Dawodu that a two year period from January 1992 to January suggests genetic disorders account for 1994. All babies were routinely examined Department of a significant proportion ofcongenital mal- within Paediatrics, Al Ain formations in the UAE and, thus, a genetic 48 hours of delivery. All cases of severe Hospital, Ministry of service should be provided congenital abnormalities which were either sus- Health, Al Ain, UAE as part of the pected or diagnosed within the first few days K Sabarinathan preventive care programme. (up to one week) were registered. Only major malformations Department of (J Med Genet were included in the study. Paediatrics, Oasis 1995;32:7-13) These were defined as those abnormalities that Hospital, Al Ain, UAE if M Varghese uncorrected or uncorrectable significantly Congenital malformations are impair normal body functions or reduce normal Correspondence to: structural ab- life expectancy.3 Congenital dislocation of the Dr Al-Gazali. normalities of prenatal origin that result from hip was not included in this study. The diag- Received 6 May 1994 defective embryogenesis or deviation from nor- Revised version accepted for mal development. The pattern and frequency nosis of congenital abnormality was based on publication 11 August 1994 clinical assessment by an experienced neo- 8 Al-Gazali, Dawodu, Sabarinathan, Varghese Table I Major congenital abnormalities in 16 419 births natologist or clinical geneticist or both and the in the UAE London Dysmorphology Database (LDDB)4 Type No IncidencellOOO births was consulted when indicated. Chromosome with mul- Multiple analysis was performed on all babies Syndromes 43 2-61 tiple abnormalities and dysmorphic features. J Med Genet: first published as 10.1136/jmg.32.1.7 on 1 January 1995. Downloaded from Sequences 12 0 73 were per- Chromosomes 28 1-70 Other appropriate investigations Association 1 0-06 formed when indicated. Necropsy was not car- Complex 1 0-06 For each Unknown 5 ried out because it is not allowed. Subtotal 90 5-48 case, a detailed pregnancy and family history, was ob- Single system including the level of consanguinity, Cardiovascular 10 0-60 tained by interviewing the parents. Central nervous system 18 1-07 into one Gastrointestinal 33 2-00 Each abnormal baby was classified Respiratory 2 0-121 of two major groups. Genitourinary 7 0-42 Musculoskeletal 5 0 30 (1) Isolated abnormalities include ab- Skin 4 0 24 Eye 2 0-12 normalities affecting a single body site. Tumours 2 0-12 (2) Multiple abnormalities are those ab- Subtotal 83 5 05 Total 173 10-5 normalities that affect more than one body site. These are further divided into: (A) Syndromes which are further sub- divided according to their aetiology Table 2 Multiple abnormalities in the UAE into monogenic, chromosomal, en- Type No of cases Family history vironmental, and syndromes of un- (parent or sib) identified aetiology. (1) Syndromes (B) Associations, which are disorders (A) Autosomal donminant Holt-Oram 2 characterised by the non-random Congenital myotonic dystrophy occurrence of several anomalies but Robinow 212 a EDS I which do not constitute specific Subtotal 6 syndrome, for example, CHARGE. Sequences include cases in which (B) Autosomal recessive (C) Joubert 2 in one the associated anomalies can be in- Goldenhar of a Larsen terpreted as a consequence OSMED + primary malformation. Roberts 2 of several Wrinkly skin syndrome (D) Complexes are anomalies EDS VII 2 different structures, all of which lie 4 SMA + together in the same body region Ophthalmoacromelia 2 01 + optic atrophy + retinopathy during embryonic development. Osteodysplastic primordial dwarfism II 1 of multiple Osteodysplastic primordial dwarfism I 4 (E) Unrecognisable patterns Kyphomelic dysplasia + tricuspid atresia l defects including patterns of mul- Congenital adrenal hyperplasia 2 that do not fit http://jmg.bmj.com/ Chondrodysplasia punctata 21 tiple abnormalities Marden Walker 21 into any of the above categories. Cerebro-oculofacioskeletal Short limb dwarfism ?type Short rib-polydactyly III Unknown + i n Spondylothoracic dysplasia Results 01 + dysmorphic features There were 173 babies with major congenital Cystic kidney and ventriculomegaly during the two year Subtotal 32 abnormalities identified period, giving an incidence of 10 5/1000 births. on September 26, 2021 by guest. Protected copyright. (C) Environmental 2 Six of these were stillbirths and 41 died in the Congenital rubella neonatal period. There were 90 babies with (D) Sporadic abnormalities and 83 ba- Noonan multiple congenital Sturge Weber bies with isolated malformations. These are in table 1. (E) Unidentified aetiology summarised Robin sequence + radial aplasia Total 43 (2) Chromosomal abnormalities MULTIPLE ABNORMALITIES (90 BABIES) Trisomy 18 3 babies) Trisomy 21 19 (A) Syndromes (43 Trisomy 13 1 + The total number of babies who had a re- 45,XO (Turner's) 2 was 43 Thirty Unbalanced translocation 2 cognised syndrome (2-6/1000). 5p- (cri du chat) 1 two of these were autosomal recessive, six were Total 28 autosomal dominant, two had congenital in- (3) Sequence fection, and two were sporadic. One baby had Holoproscencephaly 2 syndrome ofradial aplasia Potter's 6 the newly recognised Prune belly 1 and Robin sequence where the aetiology is Pierre Robin 2 The different syndromes are Amniotic band 1 still uncertain.5 Total 12 summarised in table 2. There were four babies with spinal muscle (4) Association CHARGE atrophy presenting with arythrogryposis mul- and the diagnosis was confirmed in all (5) Complexes tiplex, Poland of them by muscle biopsy. In one of these babies there was, in addition, bilateral femoral (6)1-1 Undefined- ---- abnormalities The profile of major congenital abnormalities in the United Arab Emirates (UAE) population 9 fracture noted soon after birth. This baby might dystrophy had typical features ofmyotonic dys- have the same syndrome as described by Bor- trophy and two previously affected children.