De novo balanced translocation t [6;18] [q16;q23] in a female with bilateral aniridia

A 2.5-year-old female with some dysmorphic features and bilateral aniridia was found to have de nove balanced translocation t[6;18] [q 16; q23] and normal 11p13. Fluorescence in situ hybridization using whole chromosome painting for chromosome 6 confirmed the translocation. DNA sequencing of exon 10 of PAX6 gene at aniridia [AN] locus showed no mutation. In this patient, the presence of AN with normal chromosome 11p13 and PAX6 gene probably indicates involvement of some other loci that influence the functioning of AN gene. A comparison of previously reported cases with breakpoints at 6q16 and 18q23 illustrates the frequent association of ophthalmic abnormalities as well as other clinical abnormalities

Incidence and genotype distribution of alpha-thalassemias in Kuwait

By the screening of 345 consecutive cord blood samples for hemoglobin Bart's at birth, the incidence of detectable alpha-thalassaemia among newborn Kuwaitis was estimated at 4.6% [16/345]. To determine the genotypes, DNA analysis was performed by Southern blot hybridization for the 16 samples that screened positive and for 20 consecutive samples that were negative. Of the 16 samples, 6 [1.73%] contained one gene deletion [-alpha/alpha alpha] and 9 [2.6%] contained deletion of two [-alpha/ -alpha] alpha-globin genes. In addition, a considerable proportion [4/ 20] of the consecutive samples with no detectable Hb Bart's showed a silent carrier genotype [-alpha/alpha alpha]. Using these data, the frequency of [-alpha/] haplotype is estimated at 0.16%. We conclude that the screening of alpha-thalassaemia at birth by Hb Bart's is inadequate for the Kuwaiti population due to the high proportion of samples with one gene deletion [-alpha/alpha alpha] that contained no detectable Hb Bart's