Association of matrix metalloproteinase -7 (-181A/G) promoter polymorphism in chronic pancreatitis.

Background & objectives: Chronic pancreatitis is progressive and irreversible destruction of the pancreas. Matrix metalloproteinase-7 (MMP-7) is a secreted matrilysin, which contributes to angiogenesis and breakdown of basement membranes of pancreatic tissues. The present study was aimed to investigate the association of MMP-7 −181A/G (rs11568818) gene promoter polymorphism in patients with chronic pancreatitis. Methods: A total of 100 chronic pancreatitis patients and 150 unrelated healthy individuals were included in this case control study. The genotyping of the MMP-7 gene (− 181 A/G) (rs11568818) was carried out based on PCR-RFLP. The serum levels of MMP-7 were determined by ELISA. Association between genotypes and chronic pancreatitis was examined by odds ratio (OR) with 95% confidence interval (CI). Results: The frequencies of the genotypes in promoter of MMP-7 were AA 49 per cent, AG 25 per cent and GG 26 per cent in chronic pancreatitis patients and AA 53 per cent, AG 38 per cent and GG 9 per cent in control subjects. Frequency of MMP-7 −181GG genotype and − 181G allele was significantly associated with chronic pancreatitis compared to healthy subjects [OR = 1.58 (95% CI: 1.06 –2.36), p =0.019]. There was no significant difference in the serum MMP-7 levels in the patients compared to control subjects. Interpretation &conclusions: The present study revealed a significant association of MMP-7 -181A/G (rs11568818) GG genotype with chronic pancreatitis patients, indicating its possible association with the disease.

Hidden magicians of genome evolution.

Transposable elements (TEs) represent genome’s dynamic component, causing mutations and genetic variations. Transposable elements can invade eukaryotic genomes in a short span; these are silenced by homology-dependent gene silencing and some functional parts of silenced elements are utilized to perform novel cellular functions. However, during the past two decades, major interest has been focused on the positive contribution of these elements in the evolution of genomes. The interaction between mobile DNAs and their host genomes are quite diverse, ranging from modifications of gene structure to alterations in general genome architecture and can be regarded as hidden magicians in shaping evolution of genomes. Some of the prominent examples that impressively demonstrate the beneficial impact of TEs on host biology over evolutionary time include their role in structure and functions of eukaryotic genomes.

TGF β1 -509 C/T Polymorphism in Uterine Fibroids.

Uterine leiomyomas/fibroids are the most common pelvic tumors of the female genital tract. Transforming growth factor beta (TGF β) family members are multi-functional cytokines that play a key role in cellular growth, proliferation and differentiation. The aim of this study was to investigate whether TGF β1 - 509 C/T polymorphism could be used as a susceptibility marker in Uterine fibroids pathogenesis. ARMS PCR was carried out for controls and patients (n=103) to identify the specific genotypes. Genotypes and allelic frequencies in both groups were compared. Proportions of C homozygote, heterozygote and T homozygote for TGF β1gene polymorphisms were 37.9%, 44.7%, 17.5% in the control individuals and 37%, 51.5%, 11.7% in the uterine fibroid patients. There was no significant difference between the controls and the patients thus indicating the tumor suppressor effect of TGF β1 in the early stages of tumor pathogenesis. The study was found to be in association with the earlier reported data wherein TGF β1 acts as tumor suppressor in the early stages and as a tumor promoter in the later stages of tumor pathogenesis.

Association of IL-10 & IL-10RA Polymorphisms with Lymphatic Filariasis in South Indian Population.

Aim: The filariasis infection is initiated by mosquito derived third stage larva (L3), which establishes itself in different immunocompetent niches by adopting different evasion and immunomodulatory mechanisms. Immunological and clinical outcomes can vary considerably at the individual and population levels during lymphatic filariasis infection. The protein product coded by the interleukin-10 (IL-10) gene has broad immunomodulatory function in filarial load and patency of the disease. The potential influence of altered IL-10 expression encoded by IL-10 promoter single nucleotide polymorphisms (SNPs) and IL-10RA signaling pathway, in pathogenesis and clinical outcome of filarial infection was established in the present study Study Design: Genetic association based on case-control study. Place and Duration of Study: Lymphatic filariasis cases referred to National Filariasis Control Program (NFCP), Siddipet, Medak, Andhra Pradesh, India between Feb 2006 to Dec 2009. Methodology: A total of 100 non-endemic, 50 endemic and 118 lymphatic filariasis patients were included in the present study based on clinical and diagnostic criteria. Genetic polymorphisms in the IL-10 promoter region (-1082G/A, -819C/T and -592 A/C) and IL-10 RA coding region S138G were screened following PCR-RFLP and ARMS-PCR technique respectively. Results: Patients with familial aggregation of lymphedema exhibited significant association with IL-10 -1082 ‘A’ allele (A vs G OR 2.68, CI - 1.12-6.37, P=0.02) coding for lower IL-10 levels. Similarly the G variant of IL-10RA S138G SNP revealed a significant association with lymphatic filariasis in the endemic population studied (GG vs AA OR 2.50 CI-1.22-5.13, P= 0.021). The Haplotype analysis also revealed the low signaling ATA is significantly associated with the disease in this cohort (P=0.03). The Multifactor Dimensionality Reduction Analysis (MDR) for IL-10 and IL-10RA SNPs interaction revealed the three locus model as the best model wherein the epistatic interactions of variant G allele of IL-10RA S138G, the A allele of the -1082G/A and the T allele of the -819C/T SNPs in IL-10 were found to be a possible risk genotype for filarial infection. (TA = 0.5230, CV-10/10, P=0.001). Conclusion: IL-10 promoter haplotypes and IL-10 RA S138G polymorphisms are the possible genetic determinants of susceptibility to lymphatic filariasis. Further functional studies are warranted to validate these results.

Mosaic triple X syndrome in a female with primary amenorrhea.

Background: Turner's syndrome is the most common chromosomal abnormality in females, affecting 1 in 2,500 live female births. It is a result of absence of an X chromosome or the presence of a structurally abnormal X chromosome. Its most consistent clinical features are short stature and ovarian failure. Aim: The aim of the study was to report a rare case of mosaic triple X syndrome in a female with primary amenorrhea. Materials and Methods: The chromosomal analysis using GTG banding was carried out, which revealed a mosaicism with 45,XO/47,XXX chromosomal constitution. Fluorescent in situ hybridization was also carried out to further confirm the observation made in the study. Conclusion: The physical features presented by the female could be due to the 45,XO/47,XXX mosaicism and the karyotype analysis was consistent with the diagnosis and clinical symptoms. Triple X mosaicism was confirmed with conventional and molecular cytogenetic analysis.

Epistatic interactions in idiopathic pulmonary arterial hypertension.

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) is a poorly understood complex disorder, which results in progressive remodeling of the pulmonary artery that ultimately leads to right ventricular failure. A two-hit hypothesis has been implicated in pathogenesis of IPAH, according to which the vascular abnormalities characteristic of PAH are triggered by the accumulation of genetic and/or environmental insults in an already existing genetic background. The multifactor dimensionality reduction (MDR) analysis is a statistical method used to identify gene–gene interaction or epistasis and gene–environment interactions that are associated with a particular disease. The MDR method collapses high-dimensional genetic data into a single dimension, thus permitting interactions to be detected in relatively small sample sizes. AIM: To identify and characterize polymorphisms/genes that increases the susceptibility to IPAH using MDR analysis. MATERIALS AND METHODS: A total of 77 IPAH patients and 100 controls were genotyped for eight polymorphisms of five genes (5HTT, EDN1, NOS3, ALK-1, and PPAR-γ2). MDR method was adopted to determine gene–gene interactions that increase the risk of IPAH. RESULTS: With MDR method, the single-locus model of 5HTT (L/S) polymorphism and the combination of 5HTT(L/S), EDN1(K198N), and NOS3(G894T) polymorphisms in the three-locus model were attributed to be the best models for predicting susceptibility to IPAH, with a P value of 0.05. CONCLUSION: MDR method can be useful in understanding the role of epistatic and gene–environmental interactions in pathogenesis of IPAH.

Role of matrix metalloproteinase 3 gene promoter polymorphism in chronic pancreatitis.

Aim To study the role of 5A/6A polymorphism of matrix metalloproteinase (MMP-3) and their levels in the pathogenesis of chronic pancreatitis (CP). Methods One hundred and twenty CP patients and an equal number of age and sex-matched healthy controls were included in the study. Genotypes were determined for 5A/6A allele of MMP-3 gene by allele specific PCR (AS-PCR). The serum MMP-3 levels were estimated using sandwich ELISA method. Results The distribution of the genotypes of the 5A/6A polymorphism in both control and study patients was similar (p=0.523). Within the disease group, patients with older age, early onset of the disease, and addictions such as smoking and alcohol consumption had higher levels as compared to those who did not have these features. Conclusion We conclude that functional polymorphism of MMP-3 (5A/6A) is not associated with CP. However, the higher levels within the disease group indicate its possible role in the disease process.

Novel mutations in arrhythmogenic right ventricular cardiomyopathy from Indian population.

BACKGROUND: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive condition with right ventricular myocardium being replaced by fibro-fatty tissue. The spectrum of the expression may range from benign palpitations to the most malignant sudden death. Most of the mutations identified for the condition are localized in desmosomal proteins although three other nondesmosomal genes (cardiac ryanodine receptor-2, TGF-β3, and TMEM43) have also been implicated in ARVC. Both desmosomal and nondesmosomal genes were screened in a set of patients from local population. MATERIALS AND METHODS: A set of 34 patients from local population were included in this study. Diagnosis was based on the criteria proposed by task force of European Society of Cardiology/International Society and Federation of Cardiology. Polymerase chain reaction-based single-strand conformation polymorphism analysis was carried out, and samples with abnormal band pattern were commercially sequenced. RESULTS: Screening of cardiac ryanodine receptor revealed an insertion of a base in the intronic region of exon-28 in a patient, leading to a creation of a cryptic splice site. Screening of plakohilin-2 for mutations revealed an abnormal band pattern in three patients. Two of them had similar abnormal band pattern for exon-3.1. Sequencing revealed a novel 2 base pair deletion (433_434 delCT), which would lead to premature truncation of the protein (L145EfsX8). Another patient showed abnormal band pattern for exon-3.2 and sequencing revealed a missense mutation C792T leading to amino acid change P244L, in N-terminal, and this substitution may cause disturbances in the various protein–protein interactions. CONCLUSION: This study reports novel cardiac ryanodine receptor (RyR-2) mutations and Pkp-2 for the first time from Indian population.

Genetic variations of β-MYH7 in hypertrophic cardiomyopathy and dilated cardiomyopathy.

CONTEXT: Hypertrophic cardiomyopathy (HCM) is known to be manifested by mutations in 12 sarcomeric genes and dilated cardiomyopathy (DCM) is known to manifest due to cytoskeletal mutations. Studies have revealed that sarcomeric mutations can also lead to DCM. Therefore, in the present study, we have made an attempt to compare and analyze the genetic variations of beta-myosin heavy chain gene (β-MYH7), which are interestingly found to be common in both HCM and DCM. The underlying pathophysiological mechanism leading to two different phenotypes has been discussed in this study. Till date, about 186 and 73 different mutations have been reported in HCM and DCM, respectively, with respect to this gene. AIM: The screening of β-MYH7 gene in both HCM and DCM has revealed some common genetic variations. The aim of the present study is to understand the pathophysiological mechanism underlying the manifestation of two different phenotypes. MATERIALS AND METHODS: 100 controls, 95 HCM and 97 DCM samples were collected. Genomic DNA was extracted following rapid nonenzymatic method as described by Lahiri and Nurnberger (1991), and the extracted DNA was later subjected to polymerase chain reaction (PCR) based single stranded conformation polymorphism (SSCP) analysis to identify single nucleotide polymorphism (SNP)s/mutations associated with the diseased phenotypes. RESULTS AND CONCLUSION: Similar variations were observed in β-MYH7 exons 7, 12, 19 and 20 in both HCM and DCM. This could be attributed to impaired energy compromise, or to dose effect of the mutant protein, or to even environmental factors/modifier gene effects wherein an HCM could progress to a DCM phenotype affecting both right and left ventricles, leading to heart failure.

Clinical and behavioural profile of a rare variant of klinefelter syndrome-48, XXXY.

Klinefelter’s syndrome is a sex chromosomal aneuploidy caused by an addition of X chromosome in males (47,XXY).Variants of this syndrome with X and Y polygamy are of rare occurrence. Here we describe a rare case of 48, XXXY Klinefelter’s variant from South India with a reported incidence of 1 per 17,000 to 1 per 50,000 male births. The presence of an extra X chromosome/s in these individuals has a great impact on the physical and cognitive functions, which could be attributed to gene dosage effects and genes involved in neurogenic development.

Comparison of Uhl’s anomaly, right ventricular outflow tract ventricular tachycardia (RVOT VT) & arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) with an insight into genetics of ARVD/C.

Among the right ventricular conditions, Uhl’s anomaly, arrhythmogenic right ventricular dysplasia / cardiomyopathy (ARVD/C) and right ventricular outflow tract ventricular tachycardia (RVOT VT) are disorders that exhibit pathogenic changes involving the right ventricular (RV) myocardium, and are expected to be severe or milder forms of the same condition. The review focuses on the aspect whether the three RV disorders are a spectrum of the same disease. ARVD/C is the only condition among these to be genetically well characterized. Also, variations in the clinical expression of ARVD/C due to the genetic heterogeneity are examined. Based on clinical manifestations, age at onset, gender ratio and the possible molecular mechanisms implicated, Uhl’s anomaly, ARVD/C and RVOT VT may be considered as separate entities. Further, to differentiate between the three RV disorders, the molecular studies on ARVD/C might be helpful. An attempt was made to differentiate between the eleven different types of ARVD/Cs based on clinical symptoms presented including the progression of the disease to the left ventricle, ventricular arrhythmias and clinical characteristics like ECG, SAECG, ECHO and histopathological studies.

Epidemiology and genetics of dilated cardiomyopathy in the Indian context.

Background: Dilated cardiomyopathy (DCM) still remains to be a poorly understood and less analyzed group of cardiac-muscle disorders when compared to hypertrophic cardiomyopathy (HCM). Also, the vast clinical heterogeneity among the patients has rendered the small and isolated kindred studies less informative on the genetics and epidemiology of DCM. Aim of the study: The study aimed at understanding the epidemiology and genetics of DCMs in the Indian context. Materials and methods/ Statistical analysis: One hundred seven DCM patients and 105 healthy individuals were included in the study for epidemiological and genetic risk factor identification and to fit the possible mode of inheritance. Single's ascertainment methodology for segregation analysis and Penrose frequency estimates were followed to evaluate for the role of specific epidemiological factors in the disease etiology. Chi-square analysis was carried out to interpret the results statistically. Results and Conclusion: Our study suggests that epidemiological factors like gender, age at onset and vegetarian diet in conjunction with sarcomere gene mutations may play a role in the disease expression. Similarly, segregation analysis for the possible mode of inheritance showed a deviation from the autosomal dominant mode of inheritance, strengthening the underlying genetic heterogeneity of DCM.

Linkage analysis of three families with arrythmogenic right ventricular cardiomyopathy in India.

BACKGROUND: Arrythmogenic Right Ventricular Cardiomyopathy (ARVC) is a primary myocardial disorder morphologically characterized by subtle to severe replacement of the right ventricular myocardium by fatty and fibrous tissue. ARVC is known to be highly prevalent in European population with recent reports implicating it to be a major cause of sudden death in young individuals even from American and Asian population. AIM: To implicate or exclude TMEM43 (ARVC-5), DSP(ARVC-8) genes and the yet to be identified gene at ARVC-6 locus in the pathogenesis in three families affected with ARVC from India. MATERIALS AND METHODS: Three families comprising of 42 affected/unaffected members were included in the study. Three microsatellite markers, D3S3613 (ARVC5) D10S1664 (ARVC6), D6S309 (ARVC8) were genotyped by PCR-based native PAGE. Two-point Linkage analysis was performed using LINKAGE program version 5.2 RESULTS AND DISCUSSION: LOD scores from linkage analysis for the microsatellite marker D10S1664 (ARVC-6) in families KS and REV have shown positive value hinting the involvement of this locus in the etiology of ARVC, while linkage analysis in the SB family ruled out involvement of DSP, TMEM43 and ARVC-6, as negative LOD scores were obtained with all three loci. Therefore, linkage analysis carried out in the present study indicates that ARVC-6 (cumulative LOD score is equal to plus 1.203376 at θ is equal to 0.05) could be the locus harboring the mutated gene in two out of three families.

t-plasminogen activator inhibitor-1 polymorphism in idiopathic pulmonary arterial hypertension.

AIM: The aim of the present study was to identify the possible genotypic association of 3’UTR Hind III polymorphism of Plasminogen activator Inhibitor-1 (PAI-1) gene with idiopathic pulmonary arterial hypertension (IPAH). BACKGROUND: IPAH is a disorder with abnormally raised mean pulmonary arterial pressure and increase in the resistance to blood flow in pulmonary artery. One of the pathological features seen is development of intraluminal thrombin deposition leading to thrombosis. Plasminogen activator inhibitor-1 is an important inhibitor of the fibrinolytic system; its up-regulation may suppress fibrinolysis and result in an increased risk of thrombosis. METHOD: Blood samples from 54 IPAH patients and 100 healthy voluntary donors were analyzed by PCR-RFLP method for 3’UTR Hind III polymorphism. RESULTS AND DISSCUSSION: A significant association of Hd2 allele with the disease was observed. Raised mean level of right ventricular systolic pressure was observed in the Hd2/Hd2 genotypic patients, strengthening the role of Hd2 allele in the disease progression. Our data suggests an association of Hd2/Hd2 genotype, which may lead to the up-regulation of PAI-1 gene leading to increased levels of PAI-1, which is seen in IPAH. PAI-1 competes with plasminogen activators and hinders the normal mechanism of plasminogen activation system and leads to thrombosis and formation of plexiform lesions in the lung tissue, further strengthening its role in tissue remodeling and disease progression.

Genetic variation in exon 5 of troponin - I gene in hypertrophic cardiomyopathy cases.

BACKGROUND: Cardiomyopathies are a heterogeneous group of heart muscle disorders and are classified as 1) Hypertrophic Cardiomyopathy (HCM) 2) Dilated cardiomyopathy (DCM) 3) Restrictive cardiomyopathy (RCM) and 4) Arrhythmogenic right ventricular dysplasia (ARVD) as per WHO classification, of which HCM and DCM are common. HCM is a complex but relatively common form of inherited heart muscle disease with prevalence of 1 in 500 individuals and is commonly associated with sarcomeric gene mutations. Cardiac muscle troponin I (TNNI-3) is one such sarcomeric protein and is a subunit of the thin filament-associated troponin-tropomyosin complex involved in calcium regulation of skeletal and cardiac muscle contraction. Mutations in this gene were found to be associated with a history of sudden cardiac death in HCM patients. AIM: Therefore the present study aims to identify for mutations associated with troponin I gene in a set of HCM patients from Indian population. MATERIALS AND METHODS: Mutational analyses of 92 HCM cases were carried out following PCR based SSCP analysis. RESULTS: The study revealed band pattern variation in 3 cases from a group of 92 HCM patients. This band pattern variation, on sequencing revealed base changes, one at nt 2560 with G>T transversion in exon-5 region with a wobble and others at nt 2479 and nt 2478 with G>C and C>G transversions in the intronic region upstream of the exon 5 on sequencing. Further analysis showed that one of the probands showed apical form of hypertrophy, two others showing asymmetric septal hypertrophy. Two of these probands showed family history of the condition. CONCLUSIONS: Hence, the study supports earlier reports of involvement of TNNI-3 in the causation of apical and asymmetrical forms of hypertrophy.

Epidemiology and genetics of hypertrophic cardiomyopathy.

Background: Hypertrophic cardiomyopathy (HCM) is a heart muscle disorder and is known to be inherited as an autosomal dominant trait. Mutations in several sarcomeric, cytoskeletal and mitochondrial genes have been reported in HCM. Though many cases of HCM are being identified, there is limited data regarding the epidemiology and genetics of HCM in India. Aim: Therefore the present study is envisaged at identifying the epidemiological variables in HCM and fitting a probability model assuming dominant mode of inheritance in HCM, which may in turn shed light on the heterogeneity of this complex disorder. Materials AND Methods: The 127 HCM cases were divided into subtypes based on pattern of hypertrophy. Chi square analysis, odds ratio, probability, relative frequency, penetrance and heritability estimates were calculated apart from epidemiological variables. Results: The HCM subtypes revealed the heterogeneous nature of the condition suggesting that the genes/mutations involved in their pathogenesis are different and this is supported by distinctive differences observed in their probability, heritability and penetrance estimates apart from epidemiological variables. An increased male preponderance was observed with the sex ratio being 3.7:1. The age at onset was found to be more than a decade early in familial cases (30 ± 10 yrs) compared to non familial cases (44 ± 14 yrs). Chi square analysis revealed obstructive HCM to be following autosomal dominant mode of inheritance where as non-obstructive HCM was significantly deviating. The level of deviation was significantly high for the middle onset group compared to early and late onset groups, therefore this group may be considered as an admixture wherein genes/gene modifiers and environmental variables may be contributing to the heterogeneity and this is further supported by odds ratio. Conclusions: The study thus brings out the complexity of HCM and suggests that modes of inheritance other than autosomal dominant may be encountered in a subset of HCM especially in asymmetric septal hypertrophy, apical, concentric and mid cavity obstruction subsets and hence a mixed model of inheritance is the best fit for such complex disorders.

Association of alkaline phosphatase phenotypes with arthritides.

Arthritides, a symmetrical polyarticular disease of the bone are a heterogenous group of disorders in which hereditary and environmental factors in combination with an altered immune response appear to play a causative and pathogenic role in its occurrence. Alkaline phosphatase (ALP) is an enzyme found in all tissues, with particularly high concentrations of ALP observed in the liver, bile ducts, placenta, and bone.Alkaline phosphatase is an orthophosphoric monoester phosphohydrolase catalyzing the hydrolysis of organic esters at alkaline pH, indicating that alkaline phosphatase is involved in fundamental biological processes.1 The present study envisages on identifying the specific electromorphic association of alkaline phosphatase with arthritides. Phenotyping of serum samples was carried out by PAGE (Polyacrylamide gel electrophoresis) following Davies (1964)2 protocol on 41 juvenile arthritis, 150 rheumatoid arthritis and 100 osteo arthritis apart from, 25 normal children and 100 adult healthy subjects. Phenotyping of alkaline phosphatase revealed an increase in preponderance of p+ and p++ phenotypes in juvenile, rheumatoid and osteo arthritic patients. However a significant association of these phenotypes was observed only with rheumatoid arthritis condition (c2:17.46). Similarly, a significant increase of p+ phenotypes in female rheumatoid arthritis patients was observed (c2:14.973), suggesting that the decrease in p° (tissue non specific) synthesis/secretion of alkaline phosphatase could be associated with decreased mineralization and ossification process in arthritis condition.