The frequency of Down syndrome in Libya was 1 in 516 live births. The mean age of Down mother was 35.62 years. Eighty two percent of the Down mothers were over 30 years of age as compared to 36% of the control Libyan mothers. As there was a greater percentage of late conceptions, the maternal age appears to be influential in the birth of Down syndrome in Libya. Cytogenetically 96% of the cases were that of trisomy 21. There was one case each of mosaic and 21/21 translocation, and four cases of 14/21 translocation as evidenced by Giemsa banding. Twenty two percent of the cases of Down syndrome also had other associated congenital abnormalities. The unique features involved in genetic counselling in this population are discussed. This study reflects the enormous problem of Down syndrome in the Arab world.

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The Dubai Thalassemia Center has identified 35 different beta-thalassemia mutations in 570 chromosomes from the United Arab Emirates population using gene amplification, hybridization with specific labeled oligonucleotide probes, sequencing of amplified DNA, restriction enzymes, and amplification refractory mutation system techniques. This large number of mutations which represent 21% of the total beta-mutations discovered worldwide reflects the heterogenous nature of the population living in the United Arab Emirates (1). We found that 50% of our beta-thalassemia patients have a concomitant alpha-thalassemia; namely the -alpha 3.7 kb deletion. Co-inheritance of alpha-thalassemia especially in the form of two alpha-globin gene deletions have an ameliorating effect on the phenotype presentation of our beta-thalassemia. Nine patients (one homozygote and eight compound heterozygotes) were identified with Hb Monroe (IVS-I,-1 (G-->C)), a thalassemic hemoglobin characterized by an Arg-->Thr substitution in codon 30 of the beta-globin gene. In addition, one of the patients was a compound heterozygote for Hb Tacoma [IVS-I, +1 (G-->C)]; a point mutation affecting the third nucleotide of codon 30 (G-->C) causing an Arg-->Ser replacement.

This study is to identify the various beta-thalassemic alleles in the United Arab Emirates (UAE), and compare them with the UAE residents from neighboring countries suffering from the same problem. Gene amplification, dot-blot hybridization with synthetic probes, restriction enzyme analyses, and sequencing were the tools used. Thirteen different mutations were observed in the UAE patients and seventeen mutations in the non-locals. The IVS-I-5 (G-->C) Asian Indian mutation was the most frequent mutation in both groups. Homozygous mutations in both groups were relatively higher than double heterozygous mutations.

We report on an infant with multiple congenital anomalies, tetralogy of Fallot, and Karyotype 45,X,t(Y;18)(q12;11.2). The infant's anomalies are consistent with a del(18p) syndrome, except for the exceptional severity of the heart defect.