Tahir M. Malla

GSTP1 gene Ile105Val polymorphism causes an elevated risk for bladder carcinogenesis in smokers.

BACKGROUND The glutathione S transferase (GST) family of enzymes plays a vital role in the phase II biotransformation of environmental carcinogens, pollutants, drugs and other xenobiotics. GSTs are polymorphic and polymorphisms in GST genes have been associated with cancer susceptibility and prognosis. GSTP1 is associated with risk of various cancers including bladder cancer. A case control study was conducted to determine the genotype distribution of GSTP1 A>G SNP, to elucidate the possible role of this SNP as a risk factor in urinary bladder cancer (UBC) development and to examine its correlation with clinico-pathologic variables inUBC cases. MATERIALS AND METHODS Using the polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP) approach, we tested the genotype distribution of 180 bladder cancer patients in comparison with 210 cancer-free controls from the same geographical region with matched frequency in age and gender. RESULTS We did not observe significant genotype differences between the control and bladder cancer patients overall with an odds ratio (OR)=1.23 (p>0.05). The rare allele (AG+GG) was found to be present more in cases (28.3%) than in controls (24%), though the association was not significant (p<0.05). However, a significant risk of more than 2-fold was found for the variant allele (AG+GG) with smokers in cases as compared to controls (p>0.05). CONCLUSIONS Thus, it is evident from our study that GSTP1 SNP is not implicated overall in bladder cancer, but that the rare, valine-related allele is connected with higher susceptibility to bladder cancer in smokers and also males.

Increased Micronucleus Frequency in Peripheral Blood Lymphocytes Contributes to Cancer Risk in the Methyl Isocyanate-Affected Population of Bhopal

The Bhopal gas tragedy involving methyl isocyanate (MIC) is one of the most horrific industrial accidents in recent decades. We investigated the genotoxic effects of MIC in long-term survivors and their offspring born after the 1984 occurrence. There are a few cytogenetic reports showing genetic damage in the MIC-exposed survivors, but there is no information about the associated cancer risk. The same is true about offspring. For the first time, we here assessed the micronucleus (MN) frequency using cytokinesis-blocked micronucleus (CBMN) assay to predict cancer risk in the MIC-affected population of Bhopal. A total of 92 healthy volunteers (46 MIC- affected and 46 controls) from Bhopal and various regions of India were studied taking gender and age into consideration. Binucleated lymphocytes with micronuclei (BNMN), total number of micronuclei in lymphocytes (MNL), and nuclear division index (NDI) frequencies and their relationship to age, gender and several lifestyle variabilities (smoking, alcohol consumption and tobacco-chewing) were investigated. Our observations showed relatively higher BNMN and MNL (P<0.05) in the MIC-affected than in the controls. Exposed females (EF) exhibited significantly higher BNMN and MNL (P<0.01) than their unexposed counterparts. Similarly, female offspring of the exposed (FOE) also suffered higher BNMN and MNL (P<0.05) than in controls. A significant reduction in NDI (P<0.05) was found only in EF. The affected group of non-smokers and non-alcoholics featured a higher frequency of BNMN and MNL than the control group of non-smokers and non-alcoholics (P<0.01). Similarly, the affected group of tobacco chewers showed significantly higher BNMN and MNL (P<0.001) than the non-chewers. Amongst the affected, smoking and alcohol consumption were not associated with statistically significant differences in BNMN, MNL and NDI. Nevertheless, tobacco-chewing had a preponderant effect with respect to MNL. A reasonable correlation between MNL and lifestyle habits (smoking, alcohol consumption and tobacco-chewing) was observed only in the controls. Our results suggest that EF and FOE are more susceptible to cancer development, as compared to EM and MOE. The genotoxic outcome detected in FOE reflects their parental exposure to MIC. Briefly, the observed cytogenetic damage to the MIC-affected could contribute to cancer risk, especially in the EF and FOE.

Clastogen-Induced Chromosomal Breakage Analysis of Suspected Fanconis Anemia Cases of Kashmir, North India

Clastogen induced chromosome breakage analysis is widely used for the differential diagnosis of Fanconis anemia. Mitomycin-C (MMC) induced chromosome fragility test was performed on the cultured lymphocytes of 50 children with clinical suspicion of Fanconis anemia. According to the results of the MMC test, the patients were divided into two subgroups: FA displaying typical sensitivity to MMC and non FA. The present study revealed 7(14%) of examined patients to have a FA cellular phenotype with increased MMC-induced chromosome fragility. The percentage of MMC-induced aberrant cells was increased more than 36 times in FA patients (Mean=67.14%) when compared to non FA patients (Mean=1.82). The number of MMC-induced breaks/cells was more than 09 times higher in FA patients (Mean=2.42 breaks/cell) when compared to non FA patients (Mean=0.25 breaks/cells). Our results indicate that the clastogen induced sensitivity test is a reliable in vitro method for verification of the FA cellular phenotype. The study being the first of its kind from Kashmir (North India) lays the basis for further studies on patients of this region with a clinical suspicion of FA.

Identification of Unique Pattern of CFTR Gene Mutations in Cystic Fibrosis in an Ethnic Kashmiri Population (North India)

Background: Cystic Fibrosis (CF) one of the most common severe autosomal recessive disorders is caused by mutations in CFTR gene. The mutation distributions vary widely between different geographical and ethnic groups. In view of ethnic nature of Kashmiri population (North India), we aim at looking for the 3 common mutations Δ508, 3849+10 kb, C>T and W1282X in CF suspected cases. Method: The mutations were evaluated in 150 highly suspected children with CF, proven by clinical features. ARMS-PCR was used for mutation detection of Δ508 and W1282X while as 3849+10 kb, C>T was assessed by indigenously developed ARMS-PCR and results were confirmed by RFLP. Results: Of the 150 suspected CF cases, one of the three mutations was found in 60 out of the 300 alleles genotyped. Δ508 mutation was found in 36 of 150 (24%) cases, 3849+10 kb, C>T in 24 of 150(16%) cases while as no mutation was observed in W1282X. Interestingly 08 of 09 samples with normal sweat chloride were detected positive for 3849+10 kb, C>T mutation. Conclusion: In this report, frequency of the Δ508 mutation in Kashmiri children with CF is less as compared to the Western Countries. Interestingly, we identified 3849+10 kb, C>T mutation as unique in population under study with much higher frequency as compared to rest of the world. Further we found intron 19, 3849+10 kb, C>T mutation serves as marker in those CF cases having sweat chloride negative.

Molecular and Cytogenetic Evaluation of Gender in Patients Born with Ambiguous Genitalia from Different Regions of the Valley of Kashmir,North India

Ambiguous Genitalia, a rare genetic disorder is caused by defects in the process of fetal sexual determination and differentiation where a newborn needs prompt evaluation to detect lethal conditions and gender assignment. This genetic screening is taken up with an aim to evaluate the prevalence of the patients born with Ambiguous Genitalia existing in our population. We evaluated the patients for Ambiguous Genitalia with Polymerase Chain Reaction (PCR) using SRY gene and cytogenetic analysis for detecting X and Y chromosome was performed by conventional Karyotyping. Of the 50 Ambiguous Genitalia cases, 21 (42.0 %) were detected positive for SRY gene with 46, XY Karyotype and were recognized as males while as rest of cases 29 of 50 (58%) were confirmed as females by negative SRY gene coupled with 46, XX Karyotype. All the 21 cases positive for SRY gene were cytogenetically evaluated with 46, XY except two cases, one of testicular feminization syndrome and another case of AIS where a Karyotype revealed 46, XY but were negative for SRY gene. 09 of the 50 cases (18%) had undetermined sex and among these 05 (55.5%) were found to be negative for SRY gene with 46, XX Karyotype except one case with 47, XX which was an Edward’s syndrome. 04 of the 09 cases (45.5%) were detected as males with positive SRY gene. Overall 04 cases (08.0 %) that were socially recognized as female for two decades were confirmed to be carrying Y chromosome as depicted by positive SRY gene with 46, XY Karyotype. We found that newborn with Ambiguous Genitalia exist in our region in a good number and the cytogenetic method coupled with molecular analysis by PCR are essential to unfold the sex and help in proper assignment of gender in intersex disorders.

De novo Xp terminal deletion in a triple X female with recurrent spontaneous abortions: a case report

Trisomy X (47,XXX) is a human sex chromosome aneuploidy in which females have an extra X chromosome, compared to the 46,XX karyotype in typical females. Females with 47,XXX karyotypes have been reported to have varied phenotypic changes that include features like tall stature, epicanthal folds, hypotonia and clinodactyly. Seizures, renal and genitourinary abnormalities, and premature ovarian failure are also few associated findings. However, puberty, sexual development and fertility are usually normal in trisomy X females (Tartaglia et al. 2010). The case presented in this study had two consecutive spontaneous pregnancy losses though she was devoid of any intrauterine malformation as revealed by her ultrasonography report. Her immunological profile was absolutely normal. Apparently, the female was not having any kind of facial deformity or syndromic features. Cytogenetic evaluation of the female revealed 47(XXX) karyotype with del(Xp21→Xpter) which was possibly the only discernible cause of the recurrent spontaneous abortions. Besides, karyotype analysis of the other family members revealed no structural or numerical abnormality of chromosomes. Cytogenetic evaluation of her husband revealed 46,XY karyotype. To our knowledge, till date a triple X female having recurrent spontaneous abortions with del(Xp21→Xpter) has not been reported. Trisomy X is a condition caused by the presence of an extra X chromosome in females. It is the most common chromosomal abnormality in females, occurring with an incidence of approximately 1 in 1000 female births. As some individuals are only mildly affected or asymptomatic, it is estimated that only 10% of individuals with trisomy X are actually diagnosed (Tartaglia et al. 2010). Marked facial

Molecular Identification of Intron 2 Splice Mutation and 8bp Deletion in CYP21 Gene for Congenital Adrenal Hyperplasia (CAH) Patients in Kashmir (North India)

Congenital adrenal hyperplasia (CAH) is an autosomal recessive disorder caused by alteration in CYP21 gene which ultimately leads to 21-hydroxylase deficiency. The present study aimed at evaluation of 2 common mutations viz, Intron 2 Splice (INT2S) mutation and 8 bp deletions in exon 3 of CYP21 gene and to establish their frequencies in Kashmir population (North India). The mutations were tested by Amplification Refractory Mutation System-PCR (ARMS-PCR) in 50 cases of CAH, proven by clinical features and raised 17-hydroxy progesterone (17OHP) levels. The results revealed that 15(30%) cases had INT2S mutation while as 8 bp deletion was not detected in any patient. In INT2S mutation, 7 cases were homozygous with I2-G genotype and 8 cases were heterozygous. The frequency of AG heterozygotes was found in 5 cases and CG heterozygote genotype was found in 3 cases. CAH patients with ambiguous genitalia were seen to harbor most of the INT2S mutations with I2-G in 3 cases and CG heterozygotes in 2 cases. In non-consanguineous group of patients, 4 homozygous I2-G mutations and 4 were I2- GC heterozygotes were detected in comparison to 3 and 1 in consanguineous patients respectively. Our study confirms that INT2S mutations but not 8 bp deletions exist in CYP21 gene in CAH patients in Kashmir population.

Occurrence of Chromosomal Alterations in Recurrent Spontaneous Abortion Couples: A Case-Only Study from Kashmir, North India

The present study was proposed to unveil the incidence and pattern of chromosomal abnormalities in recurrent spontaneous abortion couples of Kashmir, North India. A total of 71 couples within the age group of 24 to 42 years and having history of two or more recurrent spontaneous abortions were included in the study. Peripheral blood lymphocyte cultures were set for each subject according to standard protocol and chromosomal analysis was carried out on well spread metaphases by the help of Cytovision software Version 3.9. The incidence of chromosomal abnormalities in spontaneous abortion couples of this region was found to be 7.75% that include numerical (1.40%) as well as structural (7.75%) chromosomal abnormalities. Both males (2.11%) and females (5.63%) possessed chromosomal aberrations that comprised balanced translocations (4.22%), duplications (0.70%), deletions (0.70%) and inversions (2.11%). Besides, We report three unique balanced translocations viz., t(1;3)(q24.3;p25)(1 case); t(6,16)(p11;q23)(1 case) and t(7;14)(p13;q12)(2 cases). that have not been found elsewhere in the literature. We conclude from the present study that chromosomal alterations do occur as an etiology in the RSA couples of Kashmir and their incidence is consistent with many reports around the world. The precise molecular characterization of the unique breakpoint regions reported in our study could help in identification of new genes involved in recurrent spontaneous abortions. The study being the first of its kind in this part of the world forms the basis for further studies of the couples of this region with recurrent spontaneous abortions.