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Muhammad Ismail

Publications and source records attributed to Muhammad Ismail.

8 recordsLinked to original sources
PubMed2006

Refinement of the locus for autosomal recessive cone-rod dystrophy (CORD8) linked to chromosome 1q23-q24 in a Pakistani family and exclusion of candidate genes.

Cone-rod retinal dystrophy (CORD) characteristically leads to early impairment of vision due to the simultaneous involvement of both cone and rod photoreceptor cells. Several loci/genes have been identified for CORD, including the cone-rod dystrophy (CORD8) locus [OMIM#605549] identified for a Pakistani family. All members of this family underwent detailed clinical re-examination to determine the nature of the dystrophy. All affected individuals suffered from bilateral CORD8 with an autosomal recessive mode of inheritance. The CORD8 locus, mapped on chromosome 1q12-q24, consisted of a very large critical disease region of 21 cM. Analysis with more recently available microsatellite markers within the reported region showed heterozygosity with some of the new markers, and the crossovers lead to a refinement of the disease region from 21 to 11.53 cM. Mutation screening has excluded some of the candidate genes in the region. The disease phenotype of this family could be due to a mutation in a novel gene located within the refined CORD8 locus.

Adult↗
PubMed2004

Association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and essential hypertension in young Pakistani patients.

Several studies have demonstrated the importance of angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) polymorphisms in the pathogenesis of hypertension. This study sought to determine the association between the ACE I/D polymorphism and essential hypertension in young Pakistanis. The frequency of the ACE I/D polymorphism was established by a comparative cross-sectional survey of Pakistani patients suffering from essential hypertension and ethnically matched normotensive controls. Samples were collected from tertiary care hospitals in northern Pakistan. Hypertensive individuals were defined as those with a systolic blood pressure > 140 mmHg and/or diastolic blood pressure > 90 mmHg on three separate occasions, or those currently receiving one, or more, anti-hypertensive agents. DNA samples obtained from hypertensive (n = 211) and normotensive (n = 108) individuals were typed by PCR. The frequency of the ACE I/I genotype was significantly higher in hypertensive patients, aged 20-40 years, than in normotensive controls of the same age group (chi(2) = 4.0, P = 0.041). Whereas no overall significant differences were observed between the I/I, I/D and D/D ACE genotypes (One way ANOVA, F = 0.672; P = 0.413). The association between the ACE I/I genotype and essential hypertension in individuals aged </= 40 years suggests that ACE has a role in early onset essential hypertension in Pakistan.

Adult↗
PubMed2003

Reconstruction of human evolutionary tree using polymorphic autosomal microsatellites.

Allelic frequencies of 182 tri- and tetra-autosomal microsatellites were used to examine phylogenetic relationships among 19 extant human populations. In particular, because the languages of the Basques and Hunza Burusho have been suggested to have an ancient relationship, this study sought to explore the genetic relationship between these two major language isolate populations and to compare them with other human populations. The work presented here shows that the microsatellite allelic diversity and the number of unique alleles were highest in sub-Saharan Africans. Neighbor-joining trees based on genetic distances and principal component analyses separated populations from different continents, and are consistent with an African origin for modern humans. For the first time, with biparentally transmitted markers, the microsatellite tree also shows that the San are the first branch of the human tree before the branch leading to all other Africans. In contrast to an earlier study, these results provided no evidence of a genetic relationship among the two language isolate groups. Genetic relationships, as ascertained by these microsatellites, are dictated primarily by geographic proximity rather than by remote linguistic origin, Mantel test, R(0) = 0.484, g = 3.802 (critical g value = 1.645; P = 0.05).

Animals↗
PubMed2003

Mutation screening of Pakistani families with congenital eye disorders.

To map the disease loci several Pakistani families suffering from autosomal recessive retinitis pigmentosa with preserved para-arteriolar retinal pigment epithelium and Leber congenital amaurosis (LCA) were analyzed. Analysis revealed close genetic linkage between the disease phenotype of some of the families (3330RP, 111RP and 010LCA) and the microsatellite markers on chromosome 1q31. Mutation screening of the candidate gene CRB1 revealed a G to A transversion in exon 7 in arRP family 330RP and a T to C substitution in another arRP family, 111RP. In exon 9 of the CRB1 gene a T to C transversion was found in the family suffering from LCA (010LCA). The LCA phenotype of another family (011LCA) in which the CRB1 locus was excluded, showed linkage with microsatellite markers D17S1294 and D17S796 on chromosome 17p13.1. The association of the candidate gene GUCY2D (17p13.1) with the disease phenotype was excluded as no disease-associated mutation was found in any of its exons. Mutation screening of another candidate gene, AIPL1 located in the same region, showed a novel homozygous C to A substitution in exon 2. These sequence changes are unique for the Pakistani families and some of these have not been reported previously.

Adolescent↗
PubMed2002

A novel locus for autosomal dominant nuclear cataract mapped to chromosome 2p12 in a Pakistani family.

PURPOSE: To map the disease locus in a four-generation, consanguineous Pakistani family affected by autosomal dominant congenital nuclear cataract (adNCat). All affected individuals had early onset of bilateral nuclear cataract. METHODS: Genomic DNA from family members was typed for alleles at more than 300 known polymorphic genetic markers by polymerase chain reaction. The lod scores were calculated by using two-point linkage analysis of the genotyping data. RESULTS: The maximum lod score, 4.05, was obtained for the marker D2S2333. Proximal and distal crossovers were observed with markers D2S286 and D2S1790, respectively. These crossovers define the critical disease locus to an interval of approximately 9 centimorgans (cM). CONCLUSIONS: Linkage analysis identified a novel locus for adNCat on chromosome 2p12 in a Pakistani family. A genome database analysis of the target interval is being undertaken to identify candidate gene(s) for the disease.

Adult↗
PubMedDate not supplied

Ocular defects in first generation of ethanol exposed albino rats and its penetrance into third generation.

BACKGROUND: The objective of this study was to observe the ocular teratogenic effects of alcohol on the third generation in albino rats. METHODS: This study was carried out at department of Anatomy, Basic Medical Sciences Institute, JPMC Karachi from 1996--98. 36 pregnant female rats were divided into a treated and a control group (18 in each). The gestation period of albino rats is between 21-23 days (7 days trimester). Treated group was injected 25% alcohol (ethanol) intraperitonealy in a dose of 0.03 ml/gm body weight, while the control group was treated with normal saline in the same dose by same route. This intervention was done on 8th, 9th and 10th gestational day. The first generation (n=115) was crossbred to get second generation (n=104) that was then used to produce the third generation (n=95). Generations of control rats were developed parallel. No treatment was given to the subsequent generations of treated or control groups. RESULTS: Ocular defects (micro/macrophthalmia, cataract, coreanl opacity etc.) were observed in 30% (39/115) of the first generation, 40.38% (42/104) of the second generation and 45.26% (43/95) of 3rd generation of ethanol treated group. No ocular defect was observed in the three generations of controls. CONCLUSION: Alcohol exposure caused ocular defects in three generations of exposed rats. There is a need to study subsequent generations of rats for further penetrance and to develop cohort study in humans.

Animals↗