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News & Press Release - 2003
Arab Genomic Studies
Study discovers rare case of X chromosome
27 Jun 2003

A rare case of '49,XXXXY' syndrome - X chromosome aneuploidy - which results in multiple malformations and delayed psychomotor development, was discovered in a UAE national boy at birth. The study was carried out to collect data on genetic diseases in the UAE.

The Centre for Arab Genomic Studies (CAGS) project, launched by the UAE Minister of Health last week, aims at identifying disease-causing genes in the Arab population and to develop a database of genetic diseases prevalent in the Arab world.

Although 47,XXX, 47,XXY, 47,XYY and 45,X karyotypes are frequent and occur in at least one in every 400 births, patients with more than one extra sex chromosomes are very rare.

One such case is a three-and-half-year old male patient born to blood-related UAE national parents was referred to the genetics clinic for evaluation for dysmorphic features. He has three normal elder siblings, two females and one male. His mother had two spontaneous abortions in the first trimester.

His antenatal period was uneventful. He was delivered by caesarian section at full term because of foetal distress. The weightage at the time of birth was 1.5kg. He had feeding-difficulty in the neonatal period in view of the cleft palate, in addition to recurrent lower respiratory infections and behavioural disorders.

These clinical findings were consistent with diagnosis for 49,XXXXY syndrome that was confirmed by cytogenetic studies. Chromosomal analyses of both parents were normal.

Among the genetic diseases on which data has been collected in the UAE and which is currently available on the CAGS's online database, are: Down Syndrome, Edwards Syndrome, Klinefelter Syndrome, Patau Syndrome, Ring Chromosome, Thalassemia beta, Turner Syndrome and West Syndrome.

The number of Thalassemia beta cases recorded in the UAE among both local and expatriate populations came to 167, with 31 mutations. Thalassemia is a life-long debilitating genetic disease that results in the body's inability to produce adequate amounts of Hoemoglobin inside the red blood cells.

The result is severe anaemia. Children suffering from this blood disorder require blood transfusions every month of their lives in addition to treatment for iron overload due to the excessive number of transfusions.

Recent studies show that eight to ten per cent of UAE nationals are carriers of the Beta-globin gene located on Chromosome 11 of human DNA. Carriers of this gene, should they marry other carriers, would risk giving birth to children suffering from Thalassaemia Major, a rare but severe anemia that requires regular blood transfusions and treatment for iron overload.

Dr Mahmood Taleb, Chairman of the Emirates Thalassaemia Society (ETS) and Director of the CAGS Executive Committee, pointed to the pressing need to spread awareness about this disease among the general population and encourage people to have pre-marital blood tests as a means to screen carriers of the Beta-globin gene...