Analysis of the D1S80 (pMCT118) VNTR locus polymorphism in a native Kuwaiti population by the polymerase chain reaction.

We have determined the allele and genotype frequencies at the hypervariable locus D1S80 in a native Kuwaiti population using the polymerase chain reaction technique and subsequent high resolution gel electrophoresis. In a sample of 200 individuals, 21 alleles and 57 genotypes were detected. The alleles with 18 and 24 repeat units were most common with frequencies of 0.188 and 0.408 respectively. The distribution of the observed genotypes was in agreement with the Hardy-Weinberg equilibrium prediction. The observed heterozygosity for the population sample was 0.80 with the allelic diversity of 0.781 +/- 0.029 and the power of discrimination was 0.94. The data obtained in this study are potentially useful for individual identification in forensic casework.

Sporadic occurrence of nondeletion Prader-Willi syndrome in two cases: a female with maternal uniparental disomy and a male with complex chromosomal rearrangement.

We report here two cases of nondeletion Prader-Willi syndrome (PWS). Case 1 is a 9-yr-old female patient with classical features of the syndrome and cytogenetically normal chromosome 15. DNA analysis using polymorphic probes for Prader-Willi Critical Region (PWCR) showed absence of paternal alleles while maternal uniparental isodisomy (UPisoD) was confirmed. This is the first report of nondeletion PWS with uniparental disomy (UPD) in the population of Kuwait. The second case with Prader-Willi syndrome-like features had normal chromosome 15 but showed familial complex chromosomal rearrangement (CCR) involving chromosomes 13, 19, and 20 inherited from his mother. No paternal deletion or UPD disomy was observed after DNA molecular analysis. This is a case of "atypical" PWS with no cytogenetic or molecular abnormality for PWCR. The two cases represent two different mechanisms associated with nondeletion PWS.

HLA-DQ alpha allele and genotype frequencies in a native Kuwaiti population.

We report the allele and genotype frequencies in a sample of an unrelated native Kuwaiti population determined by the use of polymerase chain reaction (PCR) and reverse dot-blot analysis. This technique, involving the use of commercially available AmpliType HLA-DQ alpha forensic DNA amplification and typing kit, has permitted the definition of six alleles and 21 genotypes in a sample of 220 people. The allelic frequencies are in the range 5.7-27.5%. This locus demonstrated a heterozygosity of 0.80 with an allelic diversity of 0.81 and the power of discrimination (PD) was 0.93. The distribution of observed genotypes conformed to Hardy-Weinberg equilibrium thus indicating genetic equilibrium of the different variants. This population data should permit the use of HLA-DQ alpha marker for individual identification in forensic casework.

Chemical modification of rat liver cytosolic NADP(+)-linked isocitrate dehydrogenase by N-ethylmaleimide. Evidence for essential sulphydryl groups.

Incubation of rat liver cytosolic isocitrate dehydrogenase with N-ethylmaleimide (NEM) resulted in the inactivation of the enzyme following pseudo-first order kinetics. Isocitrate affords considerable protection against inactivation whereas NADP+ enhances modification of the enzyme, suggesting localization of the modified group at the active site. Correlation of loss of activity with incorporation of [14C]NEM indicated that two sulphydryl residues/sub-unit are modified of which only one is shown to be involved in catalysis. pH dependence of the inactivation process implicates a reactive group of pKa 8.1 in catalysis. We conclude that a unique cysteine residue is essential for maximal catalytic activity of isocitrate dehydrogenase.

Purification and partial characterisation of NADP(+)-linked isocitrate dehydrogenase from rat liver cytosol.

NADP(+)-linked isocitrate dehydrogenase from rat liver cytosol was purified (approximately 135-fold) to apparent homogeneity in 27% yield. The purified enzyme has specific activity of 73 units.mg-1. The native enzyme showed an apparent M(r) of 94,000 by gel filtration and was composed of two identical subunits of M(r) 45,000 as judged by SDS/PAGE. In isoelectric focusing, a pI value of 5.7 was estimated for the enzyme.

Heredity of asthma in Saudi population.

In a cross-sectional study, the prevalence of asthma, hay fever and eczema was studied in 1150 schoolchildren attending school in Jeddah Western region of Saudi Arabia. The family histories of asthma, hay fever and eczema were examined in first degree relatives. The age range of children studied was 7-12 years, with a mean of 9.3 years (47% boys and 53% girls). A self-administered questionnaire was completed by the parents of the child to collect information concerning bronchial asthma, hay fever, and eczema in the target child and family history of respiratory allergy. A detailed family history and personal histories of asthma were available for 1035 Saudi children aged 7-12 years old. The rate of asthma and hay fever were significantly higher among siblings and offspring (cases) compared to their parents (p < 0.001). The results showed a high positive correlation between the relatives of affected children with respect to asthma and hay fever. These findings support the hypothesis that asthma and hay fever may be inherited in the Saudi population, but the mode of inheritance has yet to be determined.

Epidemiology of multiple sclerosis in Arabs in Kuwait: a comparative study between Kuwaitis and Palestinians.

On December 31, 1988 there were 201 registered multiple sclerosis patients in Kuwait, an overall prevalence rate (PR) of 10.2 per 100,000; among them were 186 Arabs, of whom 72 were Palestinians and 51 Kuwaitis. Comparison of these two subgroups, who had a similar age distribution revealed that the disease was 2 1/2 times more frequent among Palestinians (PR 23.8/100,000) than among Kuwaitis (PR 9.5/100,000). Palestinians also showed significant differences from Kuwaitis in eye color, blood group distribution and HLA-DR and HLA-DQW epitopes frequency. This suggests that genetic rather than environmental factors might be the underlying cause for the high susceptibility to develop MS among Arabs originating from the Eastern Mediterranean basin.

Autosomal recessive ataxia, slow eye movements, dementia and extrapyramidal disturbances.

An Arab family with an autosomal recessive form of spinocerebellar degeneration with slow eye movements is reported. Hitherto all the reported cases were either sporadic or of autosomal dominant inheritance. Associated are progressive intellectual impairment and extrapyramidal dysfunction as well as peripheral neuropathy and skeletal abnormalities. Muscle biopsy revealed non-specific mitochondrial abnormalities. The spectrum of eye movement abnormalities is discussed and the literature is reviewed. It is concluded that the hallmark of this syndrome (slow or even absent saccades) is one of a group of oculomotor abnormalities, all being characterized by delayed initiation and slow velocity. The syndrome seems to be related to the olivopontocerebellar degenerations, but differs in that there is in addition selective degeneration of certain tracts and nuclei in the mesencephalon and probably more rostral structures.

Late onset cerebello-pontomesencephalic degeneration.

Two siblings are presented with late onset, rapidly progressive truncal ataxia, paralysis of down-gaze and loss of up-gaze saccades in association with other oculomotor dysfunctions as well as dementia. Electron microscopic muscle studies revealed abnormal distribution and form of the mitochondria, probably being the ultrastructural basis of the pathologic changes. A neurological syndrome as that described here has not been reported before.

Autosomally inherited recessive spastic ataxia, macular corneal dystrophy, congenital cataracts, myopia and vertically oval temporally tilted discs. Report of a Bedouin family--a new syndrome.

A Bedouin family is described with an unusual form of spinocerebellar degeneration. Spastic ataxia was found to be associated with congenital cataracts, macular corneal dystrophy and non-axial myopia, in the absence of retardation of somatic or mental maturation. Immunological abnormalities were common. Genetic analysis revealed that the pedigree is expressing the transmission and segregation of a single mutant autosomal recessive gene.

The genetic structure of the Kuwaiti population. I. Distribution of 17 markers with genetic distance analysis.

Frequency estimates were determined on seventeen blood group, serum protein, and red-cell enzyme markers on random samples of 193 individuals from two Bedouin tribes in addition to the general population in Kuwait. Genetic heterogeneity between the three communities is evident from the significant differences in allelic distribution of the polymorphic markers. Genetic distance measurements were used to compare the results with the oral history of descent of the two tribal communities. Results were in agreement with tribal history.