A novel ZRS variant causes preaxial polydactyly type I by increased sonic hedgehog expression in the developing limb bud.

PURPOSE: Preaxial polydactyly (PPD) is a common congenital hand malformation classified into four subtypes (PPD I-IV). Variants in the zone of polarizing activity regulatory sequence (ZRS) within intron 5 of the LMBR1 gene are linked to most PPD types. However, the genes responsible for PPD I and the underlying mechanisms are unknown. METHODS: A rare large four-generation family with isolated PPD I was subjected to genome-wide genotyping and sequence analysis. In vitro and in vivo functional studies were performed in Caco-2 cells, 293T cells, and a knockin transgenic mouse model. RESULTS: A novel g.101779T>A (reference sequence: NG_009240.2; position 446 of the ZRS) variant segregates with all PPD I-affected individuals. The knockin mouse with this ZRS variant exhibited PPD I phenotype accompanying ectopic and excess expression of Shh. We confirmed that HnRNP K can bind the ZRS and SHH promoters. The ZRS mutant enhanced the binding affinity for HnRNP K and upregulated SHH expression. CONCLUSION: Our results identify the first PPD I disease-causing variant. The variant leading to PPD I may be associated with enhancing SHH expression mediated by HnRNP K. This study adds to the ZRS-associated syndromes classification system for PPD and clarifies the underlying molecular mechanisms.

ddRAD sequencing-based identification of inter-genepool SNPs and association analysis in Brassica juncea.

BACKGROUND: Narrow genetic base, complex allo-tetraploid genome and presence of repetitive elements have led the discovery of single nucleotide polymorphisms (SNPs) in Brassica juncea (AABB; 2n = 4x = 36) at a slower pace. Double digest RAD (ddRAD) - a genome complexity reduction technique followed by NGS was used to generate a total of 23 million paired-end reads from three genotypes each of Indian (Pusa Tarak, RSPR-01 and Urvashi) and Exotic (Donskaja IV, Zem 1 and EC287711) genepools. RESULTS: Sequence data analysis led to the identification of 10,399 SNPs in six genotypes at a read depth of 10x coverage among the genotypes of two genepools. A total of 44 hyper-variable regions (nucleotide variation hotspots) were also found in the genome, of which 93% were found to be a part of coding genes/regions. The functionality of the identified SNPs was estimated by genotyping a subset of SNPs on MassARRAY® platform among a diverse set of B. juncea genotypes. SNP genotyping-based genetic diversity and population studies placed the genotypes into two distinct clusters based mostly on the place of origin. The genotypes were also characterized for six morphological traits, analysis of which revealed a significant difference in the mean values between Indian and Exotic genepools for six traits. The association analysis for six traits identified a total of 45 significant marker-trait associations on 11 chromosomes of A- and B- group of progenitor genomes. CONCLUSIONS: Despite narrow diversity, the ddRAD sequencing was able to identify large number of nucleotide polymorphisms between the two genepools. Association analysis led to the identification of common SNPs/genomic regions associated between flowering and maturity traits, thereby underscoring the possible role of common chromosomal regions-harboring genes controlling flowering and maturity in Brassica juncea.

Mutations Preventing Regulated Exon Skipping in MET Cause Osteofibrous Dysplasia.

The periosteum contributes to bone repair and maintenance of cortical bone mass. In contrast to the understanding of bone development within the epiphyseal growth plate, factors that regulate periosteal osteogenesis have not been studied as intensively. Osteofibrous dysplasia (OFD) is a congenital disorder of osteogenesis and is typically sporadic and characterized by radiolucent lesions affecting the cortical bone immediately under the periosteum of the tibia and fibula. We identified germline mutations in MET, encoding a receptor tyrosine kinase, that segregate with an autosomal-dominant form of OFD in three families and a mutation in a fourth affected subject from a simplex family and with bilateral disease. Mutations identified in all families with dominant inheritance and in the one simplex subject with bilateral disease abolished the splice inclusion of exon 14 in MET transcripts, which resulted in a MET receptor (MET(Δ14)) lacking a cytoplasmic juxtamembrane domain. Splice exclusion of this domain occurs during normal embryonic development, and forced induction of this exon-exclusion event retarded osteoblastic differentiation in vitro and inhibited bone-matrix mineralization. In an additional subject with unilateral OFD, we identified a somatic MET mutation, also affecting exon 14, that substituted a tyrosine residue critical for MET receptor turnover and, as in the case of the MET(Δ14) mutations, had a stabilizing effect on the mature protein. Taken together, these data show that aberrant MET regulation via the juxtamembrane domain subverts core MET receptor functions that regulate osteogenesis within cortical diaphyseal bone.

A meta-analysis identifies adolescent idiopathic scoliosis association with LBX1 locus in multiple ethnic groups.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is a common rotational deformity of the spine that presents in children worldwide, yet its etiology is poorly understood. Recent genome-wide association studies (GWAS) have identified a few candidate risk loci. One locus near the chromosome 10q24.31 LBX1 gene (OMIM #604255) was originally identified by a GWAS of Japanese subjects and replicated in additional Asian populations. To extend this result, and to create larger AIS cohorts for the purpose of large-scale meta-analyses in multiple ethnicities, we formed a collaborative group called the International Consortium for Scoliosis Genetics (ICSG). METHODS: Here, we report the first ICSG study, a meta-analysis of the LBX1 locus in six Asian and three non-Asian cohorts. RESULTS: We find significant evidence for association of this locus with AIS susceptibility in all nine cohorts. Results for seven cohorts containing both genders yielded P=1.22×10-43 for rs11190870, and P=2.94×10-48 for females in all nine cohorts. Comparing the regional haplotype structures for three populations, we refined the boundaries of association to a ∼25 kb block encompassing the LBX1 gene. The LBX1 protein, a homeobox transcription factor that is orthologous to the Drosophila ladybird late gene, is involved in proper migration of muscle precursor cells, specification of cardiac neural crest cells, and neuronal determination in developing neural tubes. CONCLUSIONS: Our results firmly establish the LBX1 region as the first major susceptibility locus for AIS in Asian and non-Hispanic white groups, and provide a platform for larger studies in additional ancestral groups.

SOX9 gene shows association with adolescent idiopathic scoliosis predisposition in Northwest Indians.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is a common structural deformity of the spine affecting adolescent individuals globally. The disorder is polygenic and is accompanied by the association of various genetic loci. Genetic studies in Chinese and Japanese populations have shown the association of genetic variants of SOX9 with AIS curve severity. However, no genetic study evaluating the association of SRY-Box Transcription Factor 9 (SOX9) variants with AIS predisposition has been conducted in any Indian population. Thus, we aimed to investigate the association of the genetic variants of the SOX9 along with 0.88 Mb upstream region with AIS susceptibility in the population of Northwest India. METHODS: In total, 113 AIS cases and 500 non-AIS controls were recruited from the population of Northwest India in the study and screened for 155 genetic variants across the SOX9 gene and 0.88 Mb upstream region of the gene using Global Screening Array-24 v3.0 chip (Illumina). The statistical significance of the Bonferroni threshold was set at 0.000322. RESULT: The results showed the association of 11 newly identified variants; rs9302936, rs7210997, rs77736349, rs12940821, rs9302937, rs77447012, rs8071904, rs74898711, rs9900249, rs2430514, and rs1042667 with the AIS susceptibility in the studied population. Only one variant, rs2430514, was inversely associated with AIS in the population, while the ten variants were associated with the AIS risk. Moreover, 47 variants clustered in the gene desert region of the SOX9 gene were associated at a p-value ≤ 0.05. CONCLUSION: The present study is the first to demonstrate the association of SOX9 enhancer locus variants with AIS in any South Asian Indian population. The results are interesting as rs1042667, a 3' untranslated region (UTR) variant in the exon 3 and upstream variants of the SOX9 gene, were associated with AIS susceptibility in the Northwest Indian population. This provides evidence that the variants in the enhancer region of SOX9 might regulate its gene expression, thus leading to AIS pathology and might act as an important gene for AIS susceptibility.

Genome-wide association studies of adolescent idiopathic scoliosis suggest candidate susceptibility genes.

Adolescent idiopathic scoliosis (AIS) is an unexplained and common spinal deformity seen in otherwise healthy children. Its pathophysiology is poorly understood despite intensive investigation. Although genetic underpinnings are clear, replicated susceptibility loci that could provide insight into etiology have not been forthcoming. To address these issues, we performed genome-wide association studies (GWAS) of ∼327 000 single nucleotide polymorphisms (SNPs) in 419 AIS families. We found strongest evidence of association with chromosome 3p26.3 SNPs in the proximity of the CHL1 gene (P < 8 × 10(-8) for rs1400180). We genotyped additional chromosome 3p26.3 SNPs and tested replication in two follow-up case-control cohorts, obtaining strongest results when all three cohorts were combined (rs10510181 odds ratio = 1.49, 95% confidence interval = 1.29-1.73, P = 2.58 × 10(-8)), but these were not confirmed in a separate GWAS. CHL1 is of interest, as it encodes an axon guidance protein related to Robo3. Mutations in the Robo3 protein cause horizontal gaze palsy with progressive scoliosis (HGPPS), a rare disease marked by severe scoliosis. Other top associations in our GWAS were with SNPs in the DSCAM gene encoding an axon guidance protein in the same structural class with Chl1 and Robo3. We additionally found AIS associations with loci in CNTNAP2, supporting a previous study linking this gene with AIS. Cntnap2 is also of functional interest, as it interacts directly with L1 and Robo class proteins and participates in axon pathfinding. Our results suggest the relevance of axon guidance pathways in AIS susceptibility, although these findings require further study, particularly given the apparent genetic heterogeneity in this disease.

Cost-effective Whole Exome Sequencing discovers pathogenic variant causing Neurofibromatosis type 1 in a family from Jammu and Kashmir, India.

Neurofibromatosis type 1 (NF1) is a multisystemic hereditary disorder associated with an increased risk of benign and malignant tumor formation predominantly on the skin, bone, and peripheral nervous system. It has been reported that out of all the NF1 cases, more than 95% cases develop the disease due to heterozygous loss-of-function variants in Neurofibromin (NF1) gene. However, identification of NF1 causative variants by presently recommended method of gene-targeted Sanger sequencing is challenging and cost-intensive due to the large size of the NF1gene with 60 exons spanning about 350 kb. Further, conducting the genetic studies is difficult in low resource regions and among families with the limited financial capabilities, restricting them from availing diagnostic as well as proper disease management measures. Here, we studied a three-generation family from Jammu and Kashmir state in India, with multiple affected family members showing clinical indications of NF1. We combinedly used two applications, Whole Exome Sequencing (WES) and Sanger sequencing, for this study and discovered a nonsense variant NM_000267.3:c.2041C>T (NP_000258.1:p.Arg681Ter*) in exon 18 of NF1 gene in a cost effective manner. In silico analyses further substantiated the pathogenicity of this novel variant. The study also emphasized on the role of Next Generation Sequencing (NGS) as a cost-effective method for the discovery of pathogenic variants in disorders with known phenotypes found in large sized candidate genes. The current study is the first study based on the genetic characterization of NF1 from Jammu and Kashmir-India, highlighting the importance of the described methodology adopted for the identification and understanding of the disease in low resource region. The early diagnosis of genetic disorders would open the door to appropriate genetic counseling, reducing the disease burden in the affected families and the general population at large.

TDT-HET: a new transmission disequilibrium test that incorporates locus heterogeneity into the analysis of family-based association data.

BACKGROUND: Locus heterogeneity is one of the most documented phenomena in genetics. To date, relatively little work had been done on the development of methods to address locus heterogeneity in genetic association analysis. Motivated by Zhou and Pan's work, we present a mixture model of linked and unlinked trios and develop a statistical method to estimate the probability that a heterozygous parent transmits the disease allele at a di-allelic locus, and the probability that any trio is in the linked group. The purpose here is the development of a test that extends the classic transmission disequilibrium test (TDT) to one that accounts for locus heterogeneity. RESULTS: Our simulations suggest that, for sufficiently large sample size (1000 trios) our method has good power to detect association even the proportion of unlinked trios is high (75%). While the median difference (TDT-HET empirical power - TDT empirical power) is approximately 0 for all MOI, there are parameter settings for which the power difference can be substantial. Our multi-locus simulations suggest that our method has good power to detect association as long as the markers are reasonably well-correlated and the genotype relative risk are larger. Results of both single-locus and multi-locus simulations suggest our method maintains the correct type I error rate.Finally, the TDT-HET statistic shows highly significant p-values for most of the idiopathic scoliosis candidate loci, and for some loci, the estimated proportion of unlinked trios approaches or exceeds 50%, suggesting the presence of locus heterogeneity. CONCLUSIONS: We have developed an extension of the TDT statistic (TDT-HET) that allows for locus heterogeneity among coded trios. Benefits of our method include: estimates of parameters in the presence of heterogeneity, and reasonable power even when the proportion of linked trios is small. Also, we have extended multi-locus methods to TDT-HET and have demonstrated that the empirical power may be high to detect linkage. Last, given that we obtain PPBs, we conjecture that the TDT-HET may be a useful method for correctly identifying linked trios. We anticipate that researchers will find this property increasingly useful as they apply next-generation sequencing data in family based studies.

Metabolic syndrome and underlying genetic determinants-A systematic review.

The metabolic syndrome is a cluster of heritable and related traits which has been associated with a range of pathophysiological factors including dyslipidaemia, abdominal obesity, increased fasting plasma glucose (FPG) and hypertension. The documented genetic basis of the metabolic syndrome include several chromosomal positions, numerous candidate gene-associated polymorphisms, different genetic variants, which are linked to the syndrome either as a trait or entities mainly linked to metabolic process. Additionally, the latest findings related to the contribution of epigenetic mechanisms, microRNAs, sporadic variants, non-coding RNAs, and assessing the role of genes in molecular systems has enhanced our understanding of the syndrome. Considerable work has been done to understand the underlying disease mechanisms by elucidating its genetic etiology. Nonetheless, a common shared genetic cause has not been established to clarify the coexistence of their components and further investigation is required. While mostly neglected and rarely known, hereditary predisposition needs to be studied, including with the current defective phenotypic condition descriptions. Metabolic syndrome is a multi-faceted characteristic with abundant properties and the condition can arise from interactions between environmental variables such as physical inactivity, caloric obesity and genetic susceptibility. Although there is support for genetic determinants from family and twin research, there is still no recognised genomic DNA marker for genetic association and linkages with quite a long way off potential for clinical application. In the present review efforts have been made to through light on the various genetic determinants with large effects that underlie with the association of these traits to this syndrome. The heterogeneity and multifactorial heritability of MetS, however, has been a challenge towards understanding the factors underlying the association of these traits.

Gastric cancer in Jammu and Kashmir, India: A review of genetic perspectives.

Gastric Carcinoma (GC) is one of the most common malignancies, which accounts for 6.8% of total cancer population worldwide. In India, the northeastern region has the highest gastric cancer incidence, and the Kashmir Valley has a very high incidence of gastric cancer as compared to other parts of Northern India. It exceeds 40% of total cancers with an incidence rate of 3-6-fold higher than other metro cities of India. Gastric cancer is a heterogeneous disease where most of the cases are sporadic, and <15% are due to obvious familial clustering. The heterogeneous nature of the disease can be associated with differences in genetic makeup of an individual. A better understanding of genetic predisposition toward GC will be helpful in promoting personalized medicine. The aim of this review is to analyze the development and progression of GC and to explore the genetic perspectives of the disease with special emphasis on Jammu and Kashmir, India.

The first study of epidemiology of adolescent idiopathic scoliosis shows lower prevalence in females of Jammu and Kashmir, India.

AIS is a heterogeneous 3D spinal deformity with Cobb angle ≥10°. It affects children in the age group of 10-16 years globally with 2-3% prevalence and significant female predominance. The exact etiology of AIS is not known however, it is supposed to be associated with factors such as anthropometric, metabolic, neuromuscular abnormalities and genetics. OBJECTIVES: To determine the prevalence of AIS and association of anthropometric factors with AIS in the studied population group. METHODOLOGY: Scoliosis screening of 9,500 individuals was carried out at different educational institutions of Jammu region in Jammu and Kashmir, India using a scoliosis-meter. The subjects were later examined radiologically. RESULTS: In population of the region, AIS was most prevalent among all types of scoliosis with overall prevalence of 0.61%. The prevalence was observed to be lower in females (0.31%) than males (0.88%). Based on angle of trunk rotation (ATR), lumbar curves were more prevalent than thoracic curves. Average Cobb angle in males and females were 24.9° and 22.6°, respectively. BMI showed significant association with AIS in the age group of 12-16 years (P value =0.028). Furthermore, height was significantly associated with AIS in the overall screened population (P-value =0.029). CONCLUSIONS: The AIS patients in the Jammu region of India have unique clinical features. In contrast to the global prevalence data, the prevalence of AIS in females in the region was less in comparison to males. Based on epidemiological literature and our findings, we hypothesized that genetic factors might be a major contributor in the AIS pathogenesis along with other confounding factors such as height, BMI, ethnicity, etc.

Dual labeled fluorescence probe based qPCR assay to measure the telomere length.

Telomeres are highly repetitive regions capping the chromosomes and composed of multiple units of hexa-nucleotides, TTAGGG, making their quantification difficult. Most of the methods developed to estimate telomeres are extensively cumbersome or expensive. The quantitative polymerase chain reaction (qPCR) based assay is relatively easy and cheaper method that applies SyBr Green dye chemistry to measure telomere length. SyBr Green dye fluoresces after intercalation into the double stranded DNA (dsDNA), thus detection of unspecific products has been a limitation as it may affect quantitation of telomeres. To overcome this limitation of SyBr Green dye, we developed a dual labeled fluorescence probe based quantitative polymerase chain reaction (qPCR) to measure the telomere length. This highly efficient, yet cost effective and easy method, utilizes a probe that targets primarily the telomeric DNA and this increases accuracy of an existing qPCR method.

Telomere Maintenance Genes are associated with Type 2 Diabetes Susceptibility in Northwest Indian Population Group.

Telomere length attrition has been implicated in various complex disorders including Type 2 Diabetes (T2D). However, very few candidate gene association studies have been carried out worldwide targeting telomere maintenance genes. In the present study, variants in various critical telomere maintenance pathway genes for T2D susceptibility in Northwest Indian population were explored. With case-control candidate gene association study design, twelve variants from seven telomere maintenance genes were evaluated. Amongst these five variants, rs9419958 (OBFC1), rs4783704 (TERF2), rs16847897 (TERC/LRRC31), rs10936599 (TERC/MYNN), and rs74019828 (CSNK2A2) showed significant association with T2D (at p-value ≤ 0.003, threshold set after Bonferroni correction) in the studied population. In silico analyses of these variants indicated interesting functional roles that warrant experimental validations. Findings showed that variants in telomere maintenance genes are associated with pathogenesis of T2D in Northwest Indian population. We anticipate further, such candidate gene association studies in other Indian populations and worldwide would contribute in understanding the missing heritability of T2D.

Review: Understanding Rare Genetic Diseases in Low Resource Regions Like Jammu and Kashmir - India.

Rare diseases (RDs) are the clinical conditions affecting a few percentage of individuals in a general population compared to other diseases. Limited clinical information and a lack of reliable epidemiological data make their timely diagnosis and therapeutic management difficult. Emerging Next-Generation DNA Sequencing technologies have enhanced our horizons on patho-physiological understanding of many of the RDs and ushered us into an era of diagnostic and therapeutic research related to this ignored health challenge. Unfortunately, relevant research is meager in developing countries which lack a reliable estimate of the exact burden of most of the RDs. India is to be considered as the "Pandora's Box of genetic disorders." Owing to its huge population heterogeneity and high inbreeding or endogamy rates, a higher burden of rare recessive genetic diseases is expected and supported by the literature findings that endogamy is highly detrimental to health as it enhances the degree of homozygosity of recessive alleles in the general population. The population of a low resource region Jammu and Kashmir (J&K) - India, is highly inbred. Some of its population groups variably practice consanguinity. In context with the region's typical geographical topography, highly inbred population structure and unique but heterogeneous gene pool, a huge burden of known and uncharacterized genetic disorders is expected. Unfortunately, many suspected cases of genetic disorders remain undiagnosed or misdiagnosed due to lack of appropriate clinical as well as diagnostic resources in the region, causing patients to face a huge psycho-socio-economic crisis and many a time suffer life-long with their ailment. In this review, the major challenges associated with RDs are highlighted in general and an account on the methods that can be adopted for conducting fruitful molecular genetic studies in genetically vulnerable and low resource regions is also provided, with an example of a region like J&K - India.

Publisher Correction: A genetic analysis identifies a haplotype at adiponectin locus: Association with obesity and type 2 diabetes.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A genetic analysis identifies a haplotype at adiponectin locus: Association with obesity and type 2 diabetes.

Adiponectin is a prime determinant of the status of insulin resistance. Association studies between adiponectin (ADIPOQ) gene single nucleotide polymorphisms (SNPs) and metabolic diseases have been reported earlier. However, results are ambiguous due to apparent contradictions. Hence, we investigated (1) the association between ADIPOQ SNPs: -11377C/G, +10211T/G, +45T/G and +276G/T for the risk towards type 2 diabetes (T2D) and, (2) genotype-phenotype association of these SNPs with various biochemical parameters in two cohorts. Genomic DNA of diabetic patients and controls from Gujarat and, Jammu and Kashmir (J&K) were genotyped using PCR-RFLP, TaqMan assay and MassArray. Transcript levels of ADIPOQ were assessed in visceral adipose tissue samples, and plasma adiponectin levels were estimated by qPCR and ELISA respectively. Results suggest: (i) reduced HMW adiponectin/total adiponectin ratio in Gujarat patients and its association with +10211T/G and +276G/T, and reduced ADIPOQ transcript levels in T2D, (ii) association of the above SNPs with increased FBG, BMI, TG, TC in Gujarat patients and (iii) increased GGTG haplotype in obese patients of Gujarat population and, (iv) association of -11377C/G with T2D in J&K population. Reduced HMW adiponectin, in the backdrop of obesity and ADIPOQ genetic variants might alter metabolic profile posing risk towards T2D.

LRFN2 gene variant rs2494938 provides susceptibility to esophageal cancer in the population of Jammu and Kashmir.

BACKGROUND: Leucine-rich repeat and fibronectin type 2 gene (LRFN2) variant rs2494938 has recently been found associated with esophageal cancer in a genome-wide association study in an Asian population. However, this association has not been replicated in any Indian population despite high incidence of the disease. MATERIALS AND METHODS: In the present case-control study, 166 cases and 459 controls were included. Taqman assay technique using real-time PCR was employed to investigate the association of the variant with esophageal cancer in the population of Jammu and Kashmir (J&K). The Hardy-Weinberg equilibrium for rs2494938 was assessed using the Chi-square test. The allele- and genotype-specific risk was estimated by odds ratio (OR) with 95% confidence interval (CI). RESULTS: Variant rs2494938 was observed to be significantly associated with esophageal cancer with an allelic OR of 1.59 (1.23-2.04 at 95% CI, P = 0.0003). CONCLUSION: The study highlights LRFN2 as a candidate gene for esophageal cancer susceptibility in the population of J&K and calls for a detailed study with a large sample size and involving more ethnic groups of India.

The Indian origin of paternal haplogroup R1a1* substantiates the autochthonous origin of Brahmins and the caste system.

Many major rival models of the origin of the Hindu caste system co-exist despite extensive studies, each with associated genetic evidences. One of the major factors that has still kept the origin of the Indian caste system obscure is the unresolved question of the origin of Y-haplogroup R1a1*, at times associated with a male-mediated major genetic influx from Central Asia or Eurasia, which has contributed to the higher castes in India. Y-haplogroup R1a1* has a widespread distribution and high frequency across Eurasia, Central Asia and the Indian subcontinent, with scanty reports of its ancestral (R*, R1* and R1a*) and derived lineages (R1a1a, R1a1b and R1a1c). To resolve these issues, we screened 621 Y-chromosomes (of Brahmins occupying the upper-most caste position and schedule castes/tribals occupying the lower-most positions) with 55 Y-chromosomal binary markers and seven Y-microsatellite markers and compiled an extensive dataset of 2809 Y-chromosomes (681 Brahmins, and 2128 tribals and schedule castes) for conclusions. A peculiar observation of the highest frequency (up to 72.22%) of Y-haplogroup R1a1* in Brahmins hinted at its presence as a founder lineage for this caste group. Further, observation of R1a1* in different tribal population groups, existence of Y-haplogroup R1a* in ancestors and extended phylogenetic analyses of the pooled dataset of 530 Indians, 224 Pakistanis and 276 Central Asians and Eurasians bearing the R1a1* haplogroup supported the autochthonous origin of R1a1 lineage in India and a tribal link to Indian Brahmins. However, it is important to discover novel Y-chromosomal binary marker(s) for a higher resolution of R1a1* and confirm the present conclusions.

A case report on a novel MT-ATP6 gene variation in atypical mitochondrial Leigh syndrome associated with bilateral basal ganglia calcifications.

Leigh Syndrome (LS) is a rare, hereditary progressive neurodegenerative disorder of infancy or early childhood associated with a highly variable clinical presentation even among siblings. Further, genetic heterogeneity makes its diagnosis complicated. Its causative genetic variations are notified in some of the mitochondrial and nuclear genes. Here, we report an atypical case of LS in a 9-year-old boy associated with a novel variation in MT-ATP6 gene. The atypical findings were Bilateral Basal Ganglia Calcification (BGC) and late survival age in the patient. Analyses of the Whole Mitochondrial Genome Sequencing (WMGS) results of the recruited patient and his mother at different read coverage, first at 100× and later repeated at 500×, revealed a novel disease-associated variation in the already known disease-associated MT-ATP6 gene. In conclusion, the present study indicates amalgamation of both neuro-imaging and Next Generation Sequencing (NGS) Technologies aiding the proper diagnosis of LS in atypical cases.

Concomitant presence of mutations in mitochondrial genome and p53 in cancer development - a study in north Indian sporadic breast and esophageal cancer patients.

Mitochondrial DNA alterations in recent years have been suggested as modifier events, providing a possible proliferative advantage to the tumor cells. In order to provide further insight into the process of tumorigenesis, a study of whole mitochondria genome was conducted in 134 tissue samples obtained from 2 unrelated cancers (tumor and adjacent normal tissues from 36 breast cancer and 31 esophageal squamous cell carcinoma (ESCC) patients) with known p53 somatic mutation background. Fifteen of 36 (41.66%) breast and 12 of 31 (38.71%) ESCC tumors were found to contain at least 1 mtDNA somatic mutation, which correlated significantly with the concomitant presence of somatic mutation in DNA binding domain of the p53 gene (Breast cancer, p = 0.006; ESCC, p = 0.002). Interestingly, mutations in the non D-loop region of the mtDNA contributed significantly (Breast cancer, p = 0.004; ESCC, p = 0.032) in comparison to the hotspot-D-Loop-region. The concomitant presence of mutations in p53 and mtDNA were also predominant in breast cancer tumors with poor prognosis, that is, with the advanced stage, grade and the ER/PR negativity. Also, the observation made was apparently well explained in 10398A bearing N haplogroup genetic background with increased presence of novel and pathogenic germline mutation in mtDNA. Our study suggests that the concomitant presence of somatic alteration in mtDNA and the DNA binding domain of the p53 gene facilitates cell survival and tumorigenesis, requiring specialized therapeutic intervention because of a possible resistance to conventional chemotherapy.