Associations of angiotensinogen gene mutations with hypertension and myocardial infarction in a gulf population.

To date, the human angiotensinogen (AGT) gene and some of its variants represent the best examples of genetic influences that are involved in the determination of essential hypertension (EH) and associated cardiovascular diseases (CVDs). To assess the value of genotyping AGT in a genetically homogeneous population, we carried out a retrospective, case control study of variants M235T and T174M for putative correlations with CVDs among nationals from the United Arab Emirates (Emirati)--an ethnic group characterized by no alcohol intake and no cigarette smoking. We investigated a sample population of 229 Emirati (119 males and 110 females), comprising groups of controls and patients with clinical diagnoses of EH, left ventricular hypertrophy (LVH), ischaemic heart disease (IHD) and myocardial infarction (MI). M235T and T174M alleles were determined via assays based on the polymerase chain reaction. T174M showed no correlation with any of the four clinical entities included in this study. T235 alleles, however, occurred more frequently in the EH group and less frequently in the group of MI survivors. We also found that T235 allele frequencies decreased with age, indicating that in the Emirati population, T235 alleles are associated with a reduced life span and that this effect could occur through independent mechanisms underlying genetic susceptibilities to both EH and MI.

The angiotensin-converting enzyme (ACE) gene insertion/deletion dimorphism tracks with higher serum ace activities in both younger and older subjects.

BACKGROUND: The absence of a 287 base pair alu sequence in the ACE gene (D allele) is associated with higher ACE levels than its presence (I allele) in adults. We carried out a case-control study of the ACE*I/D dimorphism in relation to circulating ACE activities to evaluate associations between the two variables in adults, compared to younger (18 years or less) individuals. MATERIALS AND METHODS: Genotypes of the ACE*I/D dimorphism were determined on DNA samples from a population of 164 random (unrelated) Emirate nationals, composed of two groups: 112 subjects above 18 years of age (range=20-77 years), and 52 subjects of 18 years or less (range=1-18), and analyzed for putative associations with serum ACE activities. ACE*I/D genotypes of the 164 individuals were determined by assays based on polymerase chain reaction. ACE activities were determined on serum samples of these subjects by colorimetric assays. RESULTS: The D allele was associated with increased ACE values in both adult and younger individuals. Mean ACE activity levels associated with II, ID and DD genotypes, however, were 42%-61% higher in the 18 years and under group of subjects. The ACE*I/D marker accounted for 28% of the variance of the phenomenon determining ACE levels in adults, and for 30% among youngsters. CONCLUSION: The ACE*I/D dimorphism correlated strongly with circulating ACE activities in both adult and young Emirati subjects, and the corresponding mean ACE activities were significantly higher among the youngsters.

SpoVH and spoVJ--new sporulation loci in Bacillus subtilis 168.

Three sporulation mutants have been isolated which produce spores with an atypical resistance phenotype, i.e. they are sensitive to organic solvents and heat but resistant to lysozyme. All three mutants produced serine protease, alkaline phosphatase and glucose dehydrogenase which are biochemical marker events for stages I, II and III. Two of the three mutants produced dipicolinic acid, a late marker, but the third was defective in its production. Heat-resistance was not restored to any of the mutants by the provision of exogenous dipicolinate. Gel electrophoresis showed that the mutant spores had similar patterns of spore coat proteins to the wild-type and electron microscopy revealed no significant structural differences. The three mutations responsible for the phenotypes of the mutant spores lie in the phe-argA region of the Bacillus subtilis chromosome. Recombination index values indicate that the mutations are in three separate genes. They define at least two new sporulation loci, designated spoVH and spoVJ.