Biomedical subjects

Mamata Deenadayal

Publications and source records attributed to Mamata Deenadayal.

12 recordsLinked to original sources

PubMed2007

The G2964A 3'-untranslated region polymorphism of the signal transducer and activator of transcription 6 gene is associated with endometriosis in South Indian women.

BACKGROUND: The aim of the study was to test whether the signal transducer and activator of transcription 6 (STAT6) gene influences the risk of developing endometriosis. METHODS: The single-nucleotide polymorphism, G2964A, in the 3'-untranslated region (UTR) of the STAT6 gene was tested for association in a case-control study of 232 affected women and 210 women with no evidence of disease. All the women were infertile, ascertained from the same infertility clinic and of South Indian origin. The genotype frequencies of this polymorphism were compared using PCR and sequencing analysis. RESULTS: There were statistically significant differences in the genotype distributions (P = 0.002) and allele frequencies (P = 0.0002) between the cases and controls, according to codominant, dominant and recessive genotype models. CONCLUSIONS: We report for the first time an association between the STAT6 G2964A 3'-UTR polymorphism and endometriosis in South Indian women. This finding suggests that STAT6 may contribute to disease susceptibility in endometriosis, which carries an extra interest as the gene lies in a region which has been implicated, albeit weakly, in a previous genomewide scan.

3' Untranslated Regions↗

PubMed2006

Missense mutations in the BMP15 gene are associated with ovarian failure.

Premature ovarian failure (POF) is an unexplained amenorrhoea (>6 months) with raised levels of gonadotropins (FSH>40 U/L) occurring before the age of 40 years. Recent studies have elucidated the role of oocyte derived growth factors (BMP15 and GDF9) in maintenance of folliculogenesis, granulosa cell (GC) proliferation and overall fertility. Our recently published work showed presence of two rare missense variants in the GDF9 gene associated with ovarian failure (Dixit et al. 2005, Menopause 12:749-754). The present case-control study has been structured to establish the role of BMP15 germline status associated with ovarian failure. Sequence analysis of the coding region of the BMP15 gene was carried out in a cohort of women with POF (n=133), primary amenorrhoea (n=60), and secondary amenorrhoea (n=9) compared with control females (n=197). This study revealed a total of 18 germline variants in the coding region of BMP15 gene, including 16 novel variants. These novel variants include one intronic variant, one 3' flanking variant, one silent variant, and 13 missense variants. Eleven missense variants were present only in cases with complete absence in the control females. The remaining two missense variants viz. c.308A>G (p.Asn103Ser) and c.788_789insTCT (p.Leu263_Arg264insLeu) were present both in the cases and in the controls. The c.788_789insTCT variant was significantly higher in primary amenorrhoea cases than in the controls (Fisher's exact test, P=0.034). Three frequent variants c.-9C>G, c.308A>G, and c.852C>T were chosen for haplotyping. The haplotype G-G-C was found to be significantly associated with ovarian failure (P=0.0075). In a nutshell, the BMP15 gene is highly associated with etiology of ovarian failure.

Adolescent↗

PubMed2005

Recurrent early pregnancy loss and endothelial nitric oxide synthase gene polymorphisms.

OBJECTIVE(S): Studies on the relation between endothelial nitric oxide synthase (eNOS) activity in implantation and maintenance of pregnancy highlights the importance of eNOS gene polymorphisms in recurrent early pregnancy loss (REPL). We investigated the relationship between idiopathic REPL and polymorphisms in eNOS among South Indian women. METHODS: A case-control study comprising 145 females with REPL and 99 control females. The polymorphisms studied include a 27 bp intron 4 repeat, Glu298Asp variation of exon 7 and a novel 140 A --> G polymorphism in intron 6. A polymerase chain reaction-based di-deoxy dye terminator sequencing method was used for genotyping. RESULTS: A novel A --> G polymorphism was identified in intron 6. The more frequent b allele of intron 4 repeat was present at a frequency of 0.84 in cases as compared to 0.86 in controls (O.R 1.17); the G allele of exon 7 coding for the wild-type glutamate containing isoform was present at a frequency of 0.79 in cases and 0.83 in controls (O.R 1.30, CI 0.6-2.8). The intron 6 variant A allele was present at a frequency of 0.58 in cases and 0.45 in controls (O.R 0.59, CI 0.33-1.08). Overall, the polymorphism in intron 6, in homozygous condition, exhibited a significant association to the risk of REPL (O.R 0.43, CI 0.21-0.89), P: 0.021). CONCLUSIONS: The present study identifies and validates a novel polymorphism in the eNOS gene which was found associated with the risk of REPL.

Abortion, Habitual↗

PubMed2005

Chromosome inversions and a novel chromosome insertion associated with recurrent miscarriages in South India.

The aim of the present study was to investigate the contribution of chromosomal abnormalities and the frequency of a particular type of aberration in couples of South Indian origin with recurrent miscarriages. A total of 160 couples with recurrent miscarriages were analyzed using Giemsa-Trypsin-Giemsa (GTG) banding and Fluorescence in situ hybridization (FISH) wherever necessary. Chromosomal abnormalities were detected in 18 individuals representing 11.25% of the samples analyzed. Present study describes majority of the cases with chromosome inversions found to be common among the referred couples. Among the abnormal karyotypes, we report for the first time an unique case of chromosome insertion in a woman with the karyotype 46,XX,ins(12;6)(q24.2;q23q25) associated with recurrent miscarriages. The overall incidence of abnormalities and the predominance of chromosome inversions indicates to physicians that routine chromosome analysis of infertile couples of South Indian origin should be essentially considered before the planning of Intra Cytoplasmic Sperm Injection (ICSI), and also the priorities for cytogenetic screening in individual cases should be established.

Abortion, Habitual↗

PubMed2005

The vascular endothelial growth factor (VEGF) +405G>C 5'-untranslated region polymorphism and increased risk of endometriosis in South Indian women: a case control study.

BACKGROUND: Vascular endothelial growth factor (VEGF), a major mediator of angiogenesis and vascular permeability, is known to play a key role in the pathophysiology of endometriosis. METHODS AND RESULTS: The single nucleotide polymorphisms, -460C>T and +405G>C, in the 5'-untranslated region of the VEGF gene were tested for association in a case-control study of 215 affected women and 210 women with no evidence of disease. All the women were of South Indian origin and ascertained from the same infertility clinic. The genotype and allele frequencies of the -460C>T polymorphism did not differ significantly between cases and controls. In contrast, the genotype (P = 0.002) and allele (P = 0.001) frequencies of the +405G>C polymorphism showed a significant difference between cases and controls. The +405 GG genotype was found more often in patients with an endometrioma >3 cm compared to controls. The frequency of the -460T/+405C haplotype (P = 0.016) was significantly lower in affected women compared to controls. CONCLUSIONS: The -460T/+405C haplotype in the VEGF gene, which is associated with lower promoter activity, was significantly less common in women with endometriosis than in controls. These data suggest that the +405G allele may influence the likelihood of a woman developing the disease.

5' Untranslated Regions↗

PubMed2005

The interleukin-6 -174G/C promoter polymorphism is not associated with endometriosis in South Indian women.

OBJECTIVE: To investigate the association of the -174 G/C promoter polymorphism of the interleukin-6 (IL-6) gene with endometriosis in South Indian women. METHODS: The genotype frequencies of the common IL-6 -174 G/C polymorphism were compared in infertility patients with (n = 232) and without (n = 210) endometriosis using polymerase chain reaction (PCR) and sequencing analysis. RESULTS: The genotype frequencies among the cases and controls were G/G 62.9% and 71.9%, G/C 34.1% and 25.2%, and C/C 3.0% and 2.9%. The G and C allele frequencies were 80% and 84.6%, and 20% and 15.4%, respectively. There were no statistically significant differences in the genotype distributions or allele frequencies between the cases and controls (P = .12). CONCLUSIONS: The present study demonstrates no significant association between the IL-6 -174 G/C promoter polymorphism and endometriosis in South Indian women.

Adult↗

PubMed2005

Prevalence of chromosome defects in azoospermic and oligoastheno-teratozoospermic South Indian infertile men attending an infertility clinic.

The prevalence of chromosomal abnormalities in azoospermic and oligoastheno-teratozoospermic infertile men of South Indian origin undergoing assisted reproductive technologies was evaluated. In addition, the study aimed to investigate new abnormal karyotypes involving autosomes in azoospermia and sex chromosomes in oligoastheno-teratozoospermic individuals that are supposed to be rare. Metaphase chromosomes of 744 infertile men, including 272 men with azoospermia and 472 men with oligoastheno-teratozoospermia (OAT), were analysed using Giemsa-trypsin-Giemsa banding and fluorescence in-situ hybridization (FISH) wherever necessary. Chromosomal abnormalities were observed in 59 (7.9%) individuals of the total studied population. Among these, 30 out of 272 (11.0%) azoospermic men and 29 out of 472 (6.1%) infertile men with OAT showed chromosomal abnormalities. A strong and statistically significant association (OR = 1.89; P = 0.0235) of chromosomal abnormalities and sex chromosome abnormalities (OR = 4.29; P = 0.001) with azoospermia when compared with OAT was observed. In addition, six autosomal abnormalities associated with azoospermia and two abnormalities involving Y chromosome, which include a novel karyotype (mos 46,XY/51,XYYYYYY) in OAT individuals, were detected.

Adult↗

PubMed2005

Novel X-chromosomal defect associated with abnormal ovarian function.

Abstract Premature ovarian failure (POF) may be idiopathic or may be associated with genetic or autoimmune disorders. It is well known that chromosomal defects can impair ovarian development and its function. It is estimated that X-chromosome abnormalities occur in 10-25% of women with abnormal ovarian function. Of these, the common chromosome defects reported are either true Turner's karyotype or its variants. We describe a novel X-chromosome aberration in a woman with primary amenorrhea. Cytogenetic and fluorescence in situ hybridization analysis revealed a short-arm deletion of X-chromosome as a Turner's variant [mos,45,XO/46,Xdel(X)(p11.1-p22.3)]. This interesting and rare case with unique X-chromosome defect reveals an additional mechanism for the cause of POF.

Adult↗

PubMed2004

Association of CYP1A1 gene polymorphism with recurrent pregnancy loss in the South Indian population.

BACKGROUND: We investigated the relationship between idiopathic recurrent pregnancy loss (RPL) and genetic polymorphisms in phase I and phase II detoxification genes which include CYP1A1, CYP2D6, GSTM1, GSTP1 and GSTT1. METHOD: A case-control study comprised 160 females with RPL and 63 healthy controls with a successful reproductive history. RESULTS: The CYP1A1 variant allele was present at frequencies of 0.61 and 0.44 in cases and controls, respectively (odds ratio=1.93; P=0.023, 95% confidence interval 1.10-3.38). The CYP2D6 variant allele was present at a frequency of 0.17 in females with RPL, while in the control population the frequency was 0.16. The GSTM1 and GSTT1 null genotypes were present at frequencies of 0.39 and 0.26 in RPL cases, whereas in controls the frequencies were 0.37 and 0.17, respectively. The mutant GSTP1 frequencies in case and control women were 0.38 and 0.40, respectively. We report a significant association of the CYP1A1*2A allele with RPL which is confirmed by logistic regression analysis. No association was observed for the other polymorphisms or in their combinations studied. CONCLUSIONS: The present study suggests the occurrence of the CYP1A1*2A allele as a probable risk factor in idiopathic recurrent miscarriages.

Abortion, Habitual↗

PubMed2004

N-acetyl transferase 2 polymorphism and advanced stages of endometriosis in South Indian women.

Aylamine-N-acetyl transferase is a phase II detoxification enzyme encoded by the gene NAT2. Single nucleotide polymorphism (SNP) changes from the wild type NAT2 *4 allele result in allelic variants *5, *6 and *7. Homozygotes for the NAT2 *4 wild type are fast acetylators; heterozygotes with one wild-type allele and a variant NAT2 *5, *6 or *7 allele have reduced enzyme activity and individuals with two variant alleles are slow acetylators. Previous studies have implicated NAT2 as a susceptibility factor in endometriosis. This study investigated the NAT2 allele frequencies and genotype distributions in 252 unrelated women with endometriosis and 264 controls of South Indian origin. No differences were found between the frequencies of fast and slow acetylators in cases (34.9% and 65.1%) and controls (33.3% and 66.7%). Two NAT2 genotypes *7/*7 (1.2%) and *5/*6/*7 (1.6%) were detected in endometriosis cases only. Four new combinations, 6D (481 + 590 mutation), 7C (590 + 857), 7D (590 + 803 + 857) and 7E (481 + 590 + 803 + 857) were detected, which have not been reported earlier. Similar genotype and phenotype results were obtained in 33 affected sister-pairs. The case-control data from this study suggest there is no association between endometriosis and NAT2 in South Indian women; however, two new variant genotypes and seven SNP combinations were also identified in cases only, which suggests that the gene may still have some as yet undetermined role in the disease.

Adolescent↗

PubMed2004

CYP1A1, GSTM1 and GSTT1 genetic polymorphism is associated with susceptibility to polycystic ovaries in South Indian women.

Polymorphic variants in the phase I enzyme, cytochrome P450 gene, may lead to increased toxification, whereas polymorphisms in the phase II enzyme, glutathione S-transferase genes, may result in impaired detoxification. Alterations in the activities of phase I drug metabolizing enzymes and phase II detoxification enzymes may cause abnormal functioning and formation of follicular cysts in the ovaries and thus causing an imbalance in the hormone profiles. This study aimed to investigate the relationship between genetic polymorphisms of CYP1A1 (T6235C), GSTM1 and GSTT1 in South Indian women with polycystic ovaries (PCO) using polymerase chain reaction-restriction fragment length polymorphism. The frequencies of variants of these genes were studied in 180 women with confirmed PCO and in 72 healthy fertile women with successful pregnancy record. No significant difference was found between the frequencies of GSTM1 and GSTT1 null genotypes in PCO cases and healthy controls. However, CYP1A1 Msp I homozygous mutants were strongly associated (P = 0.0139) with increased susceptibility to PCO. Three genotype combinations, CYP1A1 (mt/mt) with GSTM1 [-] and GSTT1 [-], CYP1A1 (wt/mt) with GSTM1 [-] and GSTT1 [-] and CYP1A1 (mt/mt) with GSTM1 [-], GSTT1 [+], were also observed in women with PCO. In conclusion, the presence of hyperinducible CYP1A1 (T6235C) mutant genotype and its mutants in combination with GSTM1 and GSTT1 null genotypes might cause an imbalance between phase I and phase II enzymes, and therefore may represent a risk factor for PCO.

Adolescent↗

PubMedDate not supplied

Chromosomal abnormalities and y chromosome microdeletions in infertile men with varicocele and idiopathic infertility of South Indian origin.

Various factors cause spermatogenesis arrest in men and, in a large number of cases, the underlying reason still remains unknown. Little attention is paid to determining the genetic defects of varicocele-related infertility. The objective of our present study was to investigate the chromosomal abnormalities and Y chromosome microdeletions in infertile men of South Indian origin with varicocele and idiopathic infertility. Metaphase chromosomes of 251 infertile men with varicocele and unexplained infertility were analyzed using Giemsa-Trypsin-Giemsa (GTG) banding and fluorescence in situ hybridization (FISH). The microdeletions in 6 genes and 18 sequence-tagged-sites (STS) in the Yq region were screened using polymerase chain reaction (PCR) techniques. Out of 251 infertile men, 57 (22.7%) men were with varicocele, of which 8.77% were azoospermic, 26.31% were severely oligozoospermic, 21.05% were mildly oligozoospermic, and 43.85% were oligoasthenoteratozoospermic (OAT), and 194 (77.29%), with idiopathic infertility, of which 51% were azoospermic, 13.40% were severely oligozoospermic, 19.07% were mildly oligozoospermic, and 16.4% were with OAT. Genetic defects were observed in 38 (15.13%) infertile individuals, including 14 (24.56%) men with varicocele and 24 (12.37%) men with idiopathic infertility. The frequencies of chromosomal defects in varicocele and idiopathic infertility were 19.3% and 8.76%, respectively, whereas Y chromosome microdeletions were 5.26% and 3.60%, respectively. Overall rate of incidence of chromosomal anomalies and microdeletions in 251 infertile men were 11.5% and 3.98%, respectively, indicating a very significant higher association of genetic defects with varicocele than idiopathic male infertility. Our data also demonstrate that, among infertile men with varicocele, severely oligozoospermic and OAT men with varicocele have higher incidences of genetic defects than mildly oligozoospermic and azoospermic men.

Adult↗