Endogamy, consanguinity and community genetics

High carrier frequency of CYP21A2 gene mutations in Southern India - underscoring the need for genetic testing in Congenital Adrenal Hyperplasia

PURPOSE

Congenital Adrenal Hyperplasia (CAH) is one of the highly prevalent autosomal recessive endocrine disorders. The majority of CAH cases result from mutations in the CYP21A2 gene, leading to 21-hydroxylase deficiency. However, with the pseudogene-associated challenges in CYP21A2 gene analysis, routine genetic diagnostics and carrier screening in CAH are not a part of the first-tier investigations in a clinical setting. Furthermore, there is a lack of data on the carrier frequency for 21-OH deficiency. Therefore, this study is aimed at investigating the carrier frequency of common pseudogene derived CYP21A2 mutations in Southern India.

METHODS

Recently, a cost-effective Allele-specific PCR based genotyping for CYP21A2 hotspot mutations has been demonstrated to be a highly specific and sensitive assay at the authors' center. Leveraging this approach, a total of 1034 healthy individuals from South India underwent screening to identify the carrier frequency of nine hotspot mutations in the CYP21A2 gene.

RESULTS

In this study, it was observed that 9.76% of the subjects were carriers for one or more of the nine different CYP21A2 mutations. Among the carriers, the most common was the large 30 kb deletion, followed by II72N, E6 CLUS, and I2G mutations.

CONCLUSION

We have identified a high prevalence of CYP21A2 mutation carriers in Southern India. These findings emphasize the importance of implementing and expanding cost-effective genetic diagnostics and carrier screening throughout India. Such initiatives would play a crucial role in managing the disease burden, enabling early intervention, and establishing guidelines for CAH newborn genetic screening in the country. This study represents the first carrier screening data on CYP21A2 hotspot mutations from India and is the largest study conducted till date in this context.

Consanguineous marriage and associated diseases among their children and grandchildren in India: evidence from large-scale data

Worldwide, more than 130 million infants are born each year and a considerable number of 13.5 million of these children have inbred parents. The present study aimed to investigate the association between parents' consanguinity and chronic illness among their children and grandchildren in India. The nationally representative data, Longitudinal Aging Study in India, 2017-2018, Wave 1 was used for the present study. Bivariate analysis, a probit model, and propensity score estimation were employed to conduct the study. The study observed the highest prevalence of consanguinity marriage in the state of Andhra Pradesh (28%) and the lowest in Kerala (5%) among the south Indian States. People who lived in rural areas, belonged to the richer wealth quintile and Hindu religion were the significant predictors of consanguinity marriage in India. For individuals who were in consanguineous marriages, there was 0.85%, 0.84%, 1.57% 0.43%, 0.34%, and 0.14% chances of their children and grandchildren developing psychotic disorders, heart disease, hypertension stroke, cancer, and diabetes, respectively. Moreover, around 4.55% of the individuals have a history of birth defects or congenital disorders. To address the risk of complicated illnesses due to the consanguinity of marriage, medical, genetic, and social counselling services are required.

Distribution of pathogenic variants in the CFTR gene in a representative cohort of people with cystic fibrosis in the Kingdom of Bahrain

BACKGROUND

Cystic fibrosis (CF) is a rare multi-systemic recessive disorder. The spectrum and the frequencies of CFTR mutations causing CF vary amongst different populations in Europe and the Middle East. In this study, we characterised the distribution of CF-causing mutations (i.e. pathogenic variants in the  CFTR gene) in a representative CF cohort from the Kingdom of Bahrain based on a three-decade-long analysis at a single tertiary centre. We aim to improve CF genetic diagnostics, introduce of CF neonatal screening and provide CFTR modulator therapy (CFTRm).

METHODS

CFTR genotyping  and associated clinical information were drawn from a longitudinal cohort. We sequenced 56 people with CF (pwCF) that had one or both CFTR mutations unidentified and carried out comprehensive bioinformatic- and family-based segregation analyses of detected variants, including genotype-phenotype correlations and disease incidence estimates. The study methodology could serve as a basis for other non-European CF populations with a high degree of consanguinity.

RESULTS

Altogether 18 CF-causing mutations  were identified, 15 of which were not previously detected in Bahrain, accounting for close to 100% of all population-specific alleles. The most common alleles comprise c.1911delG [2043delG; 22.8%], c.2988+1G > A [3120+1G>A; 16.3%], c.2989-1G>A [3121-1G>A; 14.1%], c.3909C>G [N1303K; 13.0%], and c.1521_1523delCTT [p.PheF508del; 7.6%]. Although the proportion of 1st cousin marriages has decreased to 50%, the frequency of homozygosity in our pwCF is 67.4%, thereby indicating that CF still occurs in large, often related, families. pwCF in Bahrain present with faltering growth, pancreatic insufficiency and classical sino-pulmonary manifestations. Interestingly, two pwCF also suffer from sickle cell disease. The estimated incidence of CF in Bahrain based on data from the last three decades is 1 in 9,880 live births.

CONCLUSION

The most commonCF-causing  mutations in Bahraini pwCF were identified, enabling more precise diagnosis, introduction of two-tier neonatal screening and fostering administration of CFTRm.

High Frequency of Recessive WFS1 Mutations Among Indian Children With Islet Antibody-negative Type 1 Diabetes

BACKGROUND

While the frequency of islet antibody-negative (idiopathic) type 1 diabetes mellitus (T1DM) is reported to be increased in Indian children, its aetiology has not been studied. We investigated the role of monogenic diabetes in the causation of islet antibody-negative T1DM.

METHODS

We conducted a multicenter, prospective, observational study of 169 Indian children (age 1-18 years) with recent-onset T1DM. All were tested for antibodies against GAD65, islet antigen-2, and zinc transporter 8 using validated ELISA. Thirty-four islet antibody-negative children underwent targeted next-generation sequencing for 31 genes implicated in monogenic diabetes using the Illumina platform. All mutations were confirmed by Sanger sequencing.

RESULTS

Thirty-five (21%) children were negative for all islet antibodies. Twelve patients (7% of entire cohort, 34% of patients with islet antibody-negative T1DM) were detected to have pathogenic or likely pathogenic genetic variants. The most frequently affected locus was WFS1, with 9 patients (5% of entire cohort, 26% of islet antibody-negative). These included 7 children with homozygous and 1 patient each with a compound heterozygous and heterozygous mutation. Children with Wolfram syndrome 1 (WS) presented with severe insulin-requiring diabetes (including 3 patients with ketoacidosis), but other syndromic manifestations were not detected. In 3 patients, heterozygous mutations in HNF4A, ABCC8, and PTF1A loci were detected.

CONCLUSION

Nearly one-quarter of Indian children with islet antibody-negative T1DM had recessive mutations in the WFS1 gene. These patients did not exhibit other features of WS at the time of diagnosis. Testing for monogenic diabetes, especially WS, should be considered in Indian children with antibody-negative T1DM.

Consanguineous Marriage and Its Association With Genetic Disorders in Saudi Arabia: A Review

Consanguineous marriages, where spouses are related by blood, have been a longstanding practice in human history. The primary medical concern with consanguineous marriages is the increased risk of genetic disorders. When closely related individuals reproduce, there is a higher probability that both parents carry the same genetic mutation. In Arab countries, especially Saudi Arabia, the rate of consanguineous marriage is high compared with Western European and Asian countries. This high rate is directly proportionate with elevated risk of genetic disorders, including congenital heart diseases, renal diseases, and rare blood disorders. Additionally, it was noted that the rate of negative postnatal outcomes is higher in consanguineous marriages compared with the general population. These observations indicate the necessity of tackling this area and highlighting the consequences of this practice. In this review, we aim to discuss the current evidence regarding the association between consanguineous marriages and genetic disorders in Saudi Arabia.

The role of structural racism and geographical inequity in diabetes outcomes

Diabetes is pervasive, exponentially growing in prevalence, and outpacing most diseases globally. In this Series paper, we use new theoretical frameworks and a narrative review of existing literature to show how structural inequity (structural racism and geographical inequity) has accelerated rates of diabetes disease, morbidity, and mortality globally. We discuss how structural inequity leads to large, fixed differences in key, upstream social determinants of health, which influence downstream social determinants of health and resultant diabetes outcomes in a cascade of widening inequity. We review categories of social determinants of health with known effects on diabetes outcomes, including public awareness and policy, economic development, access to high-quality care, innovations in diabetes management, and sociocultural norms. We also provide regional perspectives, grounded in our theoretical framework, to highlight prominent, real-world challenges.

Genetics of Inborn Errors of Immunity in highly consanguineous Middle Eastern and North African populations

Consanguineous marriages in Middle Eastern and North African (MENA) countries are deeply-rooted tradition and highly prevalent resulting into increased prevalence of autosomal recessive diseases including Inborn Errors of Immunity (IEIs). Molecular genetic testing is an important diagnostic tool for IEIs since it provides a definite diagnosis, genotype-phenotype correlation, and guide therapy. In this review, we will discuss the current state and challenges of genomic and variome studies in MENA region populations, as well as the importance of funding advanced genome projects. In addition, we will review the MENA underlying molecular genetic defects of over 2457 patients published with the common IEIs, where autosomal recessive mode of inheritance accounts for 76% of cases with increased prevalence of combined immunodeficiency diseases (50%). The efforts made in the last three decades in terms of international collaboration and of in situ capacity building in MENA region countries led to the discovery of more than 150 novel genes involved in IEIs. Expanding sequencing studies within the MENA will undoubtedly be a unique asset for the IEI genetics which can advance research, and support precise genomic diagnostics and therapeutics.

Examination of runs of homozygosity in relation to height in an endogamous Namibian population

OBJECTIVES

Height is a complex, highly heritable polygenic trait subject to both genetic composition and environmental influences. Recent studies suggest that a large proportion of height heritability is determined by the cumulative effect of many low allele frequency variants across the genome. Previous research has also identified an inverse relationship between height and runs of homozygosity (ROH); however, this has yet to be examined within African populations. We aim to identify this association within the Himba, an endogamous Namibian population who are recently bottlenecked, resulting in elevated haplotype sharing and increased homozygosity.

MATERIALS AND METHODS

Here, we calculate the fraction of the genome composed of long runs of homozygosity (F_ROH) in a sample of 245 adults and use mixed effects models to assess its effect on height.

RESULTS

We find that Himba adults exhibit increased homozygosity. However, in contrast to previous studies in other populations, we do not find a significant effect of F_ROH on height within the Himba. We further estimated heritability of height, noting both an enrichment of distant relatives and greater developmental homogeneity across households; we find that h g 2 = 0.59 (SE ± 0.146), comparable to estimates reported in Europeans.

DISCUSSION

Our results may be due to other environmental variables we were not able to include, measurement error, or low statistical power, but may also imply that phenotypic expression resulting from increased homozygosity may vary from population to population.

Consanguinity in the Chaouia population (Morocco): prevalence, trends, determinants, fertility, and spontaneous abortions

Background

One of the aspects that helps to understand the genetic structure of a population throughout its biological history is the description of its matrimonial practices. Thus, the objective of this study is to explore consanguinity, one of these practices, to its full extent by identifying the prevalence, determinants, and trends of a consanguineous marriage, as well as its impact on fertility and spontaneous abortions in the Chaouia population, a region located in the western center of Morocco. Therefore, a survey-based cross-sectional study was conducted between January 2019 and January 2020. The sample was collected by province using a stratified random sampling approach, yielding a sample of 788 people. The association between consanguinity and socioeconomic and demographic characteristics, as well as reproductive health and pregnancy outcomes, was described using chi-square and ANOVA analysis. Multivariate logistic regression analysis was used to determine the predictors of a consanguineous marriage.

Results

Our findings revealed a consanguinity rate of 25.38%. The mean inbreeding coefficient was 0.012214. The most common type of union was between first cousins. This practice was strongly associated with an early age at marriage for both genders and with endogamy and immobility of couples, according to their place of birth. Consanguinity was significantly associated with fertility (p < 0.001) and spontaneous abortions (p = 0.029). The average number of pregnancies and spontaneous abortions was higher in consanguineous unions (5.18 ± 0.20/0.47 ± 0.08) compared to non-consanguineous unions (4.33 ± 0.10/0.31 ± 0.03).

Conclusions

Consanguinity is a deeply rooted social and cultural tradition in this population, providing individuals with a sense of social-economic stability while assuring their attachment to the group. Despite being highly associated with fertility, this practice has a significant influence on pregnancy outcomes, namely spontaneous abortions. Therefore, further studies are needed to examine the impact of consanguinity on various aspects of reproductive health and its association with numerous genetic abnormalities and diseases.

Identifying signatures of natural selection in Indian populations

In this study, we present the results of a genome-wide scan for signatures of positive selection using data from four tribal groups (Kokana, Warli, Bhil, and Pawara) and two caste groups (Deshastha Brahmin and Kunbi Maratha) from West of the Maharashtra State In India, as well as two samples of South Asian ancestry from the 1KG project (Gujarati Indian from Houston, Texas and Indian Telugu from UK). We used an outlier approach based on different statistics, including PBS, xpEHH, iHS, CLR, Tajima’s D, as well as two recently developed methods: Graph-aware Retrieval of Selective Sweeps (GRoSS) and Ascertained Sequentially Markovian Coalescent (ASMC). In order to minimize the risk of false positives, we selected regions that are outliers in all the samples included in the study using more than one method. We identified putative selection signals in 107 regions encompassing 434 genes. Many of the regions overlap with only one gene. The signals observed using microarray-based data are very consistent with our analyses using high-coverage sequencing data, as well as those identified with a novel coalescence-based method (ASMC). Importantly, at least 24 of these genomic regions have been identified in previous selection scans in South Asian populations or in other population groups. Our study highlights genomic regions that may have played a role in the adaptation of anatomically modern humans to novel environmental conditions after the out of Africa migration.

Consanguineous marriages and their association with women's reproductive health and fertility behavior in Pakistan: secondary data analysis from Demographic and Health Surveys, 1990-2018

Background

Pakistan has been showing consistently the highest prevalence of consanguinity. The popularity of consanguineous marriages is not declining in the country, because of social, cultural, and religious beliefs as well as economic advantages. However, couples also face various health-related implications, such as poor pregnancy outcomes or multiple reproductive and fertility consequences, having adverse effects on mothers and their children. This research investigated the trend of consanguineous marriages and their association with women’s reproductive health and fertility behavior in Pakistan from 1990 to 2018.

Methods

This study is based on secondary data analysis, using all four waves of the Pakistan Demographic Health Surveys carried out from 1990 to 2018. The analysis is limited to women aged 15–49 years, who had given birth in the previous five years preceding each survey. Sampling weights were calculated and subsequently weighted analysis was conducted. Descriptive statistics, bivariable and multivariable logistic regression analysis were performed to determine the association of consanguinity with multiple characteristics related to socio-demographics, co-variates, and women’s reproductive health and fertility behaviors.

Results

The findings revealed a high but overall stable trend of consanguinity prevalence of about 63% during the last three decades. Consanguineous marriages were more prevalent amongst young and uneducated women, living in rural areas, with poorer wealth status and having less exposure to mass media to access information. A strong association of consanguinity was observed with women’s reproductive health and fertility behavior, particularly for women who gave first birth at a younger age, had multi-gravida pregnancies, multi-parity, pregnancy termination, ANC visits, and higher fertility.

Conclusion

Consanguineous marriages are predominant in the patriarchal society of Pakistan. Findings revealed that consanguinity contributes significantly to women’s reproductive health and fertility behaviors. Appropriate counseling, educational, and health promotional programs related to consanguinity should be designed and launched at the community level to raise awareness about risks towards women’s reproductive health and fertility.

Consanguineous marriage and its relevance to divorce, polygyny and survival of marriage: evidence from a population-based analysis in Jordan

BACKGROUND

Consanguinity has been extensively studied in the context of its negative health outcomes for offspring and socio-demographic factors, but little evidence-based research has been done on its potential social benefits.

AIM

To examine the association between consanguineous marriage and the risk of divorce or separation, polygyny, and survival of marriage in Jordan.

SUBJECTS AND METHODS

Data were obtained from the 2018 Jordan Population and Family Health Survey, covering a nationally representative sample of ever-married women of reproductive age. Descriptive statistics, multiple logistic regression, and survival analysis techniques were used for data analysis.

RESULTS

The prevalence of consanguineous marriage was found to be 27.5% in Jordan in 2018, while the prevalences of polygyny and divorced/separated rates were 4.4% and 4.7%, respectively. Both consanguineous and polygyny rates showed declining trends, but divorce/separation rate showed an increasing trend. Compared to non-consanguineous marriages, the risk of divorce/separation and polygyny were found to be lower among women with consanguineous marriage, while the survival of marriages was found to be higher for consanguineous marriages than for non-consanguineous marriages.

CONCLUSIONS

Findings revealed that consanguinity has some social benefits as it plays protective roles against divorce or separation, polygyny and enhances the survival of marriages.

CAH Newborn Screening in India: Challenges and Opportunities

Congenital adrenal hyperplasia (CAH) is a common treatable disorder which is associated with life-threatening adrenal crisis, sexual ambiguity, and/or abnormal growth if undiagnosed. Newborn screening is a cost-effective tool to detect affected babies early after birth to optimize their treatment and follow-up. Newborn screening however is in its nascent stage in India where it is not yet introduced universally for all babies. The following review briefly highlights the challenges (e.g., lack of universal screening, healthcare resources) and opportunities (e.g., reduction in morbidity and early correct gender assignment in females) associated with newborn screening for CAH in a large Indian birth cohort.

Prevalence and determinants of consanguineous marriage and its types in India: evidence from the National Family Health Survey, 2015-2016

The aim of the present study was to estimate the prevalence and examine the determinants of consanguineous marriage types in India. Data for 456,646 ever-married women aged 15-49 years were analysed from the National Family Health Survey (NFHS)-4 conducted in 2015-16. The overall prevalence of consanguineous marriage was 9.9%; the South region (23%) and North-East region (3.1%) showed the highest and lowest prevalences, respectively. Muslims had a higher prevalence (15%) than Hindus (9%). The prevalence of first cousin marriage (8.7%) was more than that of second cousin (0.7%) and of uncle-niece marriages (0.6%). Women living in urban areas and in nuclear families, having a higher level of education and belonging to affluent families were less likely to marry their cousins (p < 0.01). Women living in the South region of the country were more likely to marry their cousins, as well as uncles (p < 0.001). Close scrutiny of the trends in the results (odds ratios) revealed no clear relationship between socioeconomic condition and consanguineous marriage. The study results suggest that religion and north-south regional dichotomy in culture largely determine consanguineous marriage rather than socioeconomic condition in India.

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.

Genetic counseling education at the undergraduate level: An outreach initiative to promote professional recruitment and support workforce development

As in many other countries, the field of genetic counseling is in its initial stages of development in India, where there are efforts to streamline the profession and to implement graduate-level training programs. We implemented an elective course on genetic counseling at the undergraduate level in a private university in India to assess students' interest, to provide early exposure for students interested in pursuing the career, and to aid recruitment. To assess satisfaction with the course and recruitment outcomes, we sent a course evaluation survey to 332 students and received 134 responses. Familiarity with genetic counseling topics increased significantly after completing the course. Of the 42 respondents who reported they were planning to pursue formal genetic counseling training, 21% (n = 9/42) became interested in the profession as a result of taking this course. Survey respondents who were prospective applicants to genetic counseling training programs referred mostly to the websites of the National Society of Genetic Counselors and the American Board of Genetic Counseling for information on genetic counseling and training. Barriers to entry into the field included lack of shadowing opportunities, inadequate coursework, and limited opportunities to interact with practicing genetic counselors. Respondents stated that additional case studies as well as observation of patient interactions would elucidate the role of a genetic counselor and help define the scope of the practice in India and other countries. Overall, genetic counseling education at the undergraduate level is a scalable way to improve understanding of genetic counseling topics, increase professional interest in the field, and support workforce development.

Haemoglobinopathies in India: estimates of blood requirements and treatment costs for the decade 2017-2026

The Government of India is presently engaged in the implementation of a prevention and control programme for two major forms of haemoglobinopathies, thalassaemia major and sickle cell disease, with guidelines for their prevention and management formulated under the National Health Mission. Based on projections for the population up to the year 2026, the annual blood requirement for treatment will increase to 9.24 million units, together with an 86% increase in budgetary requirements which then would account for over 19% of the current National Health Budget. To avert a public health crisis there is an urgent need to fully implement the prevention programme for haemoglobinopathies.

Has the long-predicted decline in consanguineous marriage in India occurred?

To an extent the question posed in the title of this paper can simply be answered in the affirmative. Based on the extensive data available from the National Family Health Survey-1 (NFHS-1) conducted in 1992-93 and NFHS-4 in 2015-16 there has been a significant overall decline of some 19% in the prevalence of consanguineous marriage in India. However, when examined at state level the picture is more complex, with large reductions in consanguinity in southern states where intra-familial marriage previously has been strongly favoured, whereas in some northern states in which close kin unions traditionally have been proscribed small increases were recorded. In a country such as India, comprising an estimated 18% of the current world population and with multiple ethnic, religious, geographical and social sub-divisions, apparently contrary findings of this nature are not unexpected - especially given the major shifts that are underway in family sizes, in education and employment, and with rapid urbanization. The changing health profile of the population also is an important factor, with non-communicable diseases now responsible for a majority of morbidity and premature mortality in adulthood. The degree to which future alterations in the prevalence and profile of consanguineous marriage occur, and at what rate, is difficult to predict - the more so given the markedly diverse cultural identities that remain extant across the Sub-Continent, and ongoing intra-community endogamy.

Inherited Bleeding Disorders in North Indian Children: 14 years' Experience from a Tertiary Care Center

Inherited bleeding disorders are not uncommon in pediatric practice: most of them being chronic, require lifelong replacement therapy. To frame a management policy, it is essential to assess the load and pattern of bleeding disorders in the local population. However, there is paucity of data reporting the clinical spectrum of coagulation and platelet function disorders in Indian children. Hence to find out the exact burden and clinico-investigational profile of these patients we conducted this study. In this retrospective case review, detailed clinical information was extracted from case records in 426 children with a suspected diagnosis of hereditary bleeding disorder registered in the Pediatric Hematology clinic of a tertiary referral centre over a period of 14 years (1998-2011) and pooled for analysis. In our cohort prevalence of hemophilia A, hemophilia B, platelet function disorders, von Willebrand disease and other rare factor deficiencies were 72%, 11%, 7%, 4% and 4% respectively. Common clinical spectrum included skin bleeds, arthropathy, mucosal bleeds. 10% had deeper tissue bleeding and 16% received replacement therapy at the first visit. Nearly 3/4th of cases were lost for follow up after the initial visit. Hemophilia A was the commonest inherited bleeding disorder in our population. Skin bleeds and arthropathy were common clinical presentations. Factor replacement therapy was restricted to a minority. There is an urgent need for establishing centres of excellence with administrative commitment for factor replacement therapy for comprehensive management of such children in resource-limited countries.

c.1227_1228dupGG (p.Glu410Glyfs), a frequent variant in Tunisian patients with MUTYH associated polyposis

INTRODUCTION

Familial adenomatous polyposis (FAP) is an autosomal dominant-inherited disease caused by germline variants in the APC gene. It is characterized by the development of hundreds to thousands of adenomatous polyps in colon and rectum. Recently, biallelic germline variants in the base excision repair (BER) gene: MUTYH have been identified in patients with attenuated FAP and/or negative APC result. It can be responsible for an autosomal recessive inherited colorectal cancer syndrome (MAP syndrome: MUTYH-associated polyposis).

OBJECTIVE

The aim of this study was to evaluate germline variants of MUTYH gene in Tunisian patients with attenuated FAP.

METHODS

thirteen unrelated patients from Tunisia with attenuated FAP were screened for MUTYH germline variants. Direct sequencing was performed to identify point variants in this gene.

RESULTS

A Biallelic MUTYH germline variant were found in all patients and showed an attenuated polyposis phenotype almost of them without extra-colic manifestations: The known pathogenic frameshift variant c.1227_1228dupGG (p. Glu410Glyfs) was found, in homozygous state, in 13 index patients.

CONCLUSION

Patients with attenuated familial adenomatous polyposis (<=100) and no obvious vertical transmission of the disease should be considered for MUTYH gene testing.

Hemoglobinopathies in the North of Morocco: Consanguinity Pilot Study

Consanguinity is a social behavior characterized by the arrangement of marriages between relatives. It coincides generally with the geographic distribution of recessive genetic diseases as it increases the likelihood of homozygosis and, consequently, the incidence of their pathologies in the population. In this pilot study, we assess the effect of inbreeding on the burden of hemoglobinopathies in Northern Morocco. From January 2016 to December 2018, 197 children born in the studied region to three ancestral generations and diagnosed with hemoglobinopathies were subject to investigation. The rate of consanguinity in the parents' generation of children with hemoglobinopathies was 50.25%, with first cousin marriages accounting for 68.69% of consanguineous unions (FI = 0.02). The corresponding rates in the general population, based on a sample of N = 900, were 29.67% and 82.02%, respectively. The marriages between first cousins are the most common among the other types of consanguineous unions. Our study propounds that consanguinity substantially contributes to the hemoglobinopathy burden in the studied region and has changed little over time. Refraining from consanguineous marriages and detecting couples at risk could contribute to the reduction of the incidence of genetic diseases in our country.

Consanguinity and Inbreeding in Health and Disease in North African Populations

North Africa is defined as the geographical region separated from the rest of the continent by the Sahara and from Europe by the Mediterranean Sea. The main demographic features of North African populations are their familial structure and high rates of familial and geographic endogamy, which have a proven impact on health, particularly the occurrence of genetic diseases, with a greater effect on the frequency and spectrum of the rarest forms of autosomal recessive genetic diseases. More than 500 different genetic diseases have been reported in this region, most of which are autosomal recessive. During the last few decades, there has been great interest in the molecular investigation of large consanguineous North African families. The development of local capacities has brought a substantial improvement in the molecular characterization of these diseases, but the genetic bases of half of them remain unknown. Diseases of known molecular etiology are characterized by their genetic and mutational heterogeneity, although some founder mutations are encountered relatively frequently. Some founder mutations are specific to a single country or a specific ethnic or geographic group, and others are shared by all North African countries or worldwide. The impact of consanguinity on common multifactorial diseases is less evident.

Phenotyping and genotyping of skeletal dysplasias: Evolution of a center and a decade of experience in India

Genetic heterogeneity, high burden and the paucity of genetic testing for rare diseases challenge genomic healthcare for these disorders in India. Here we report our experience over the past decade, of establishing the genomic evaluation of skeletal dysplasia at a tertiary university hospital in India. Research or clinical genomic testing was carried out by Sanger sequencing and next-generation sequencing. Close national and international collaborations aided phenotyping and genotyping. We report 508 families (557 affected individuals) with the definitive molecular diagnosis of skeletal dysplasia. Dysostoses multiplex (n = 196), genetic inflammatory/rheumatoid-like osteoarthropathies (n = 114) and osteogenesis imperfecta and decreased bone density (n = 58) were the most common diagnoses. We enumerate the processes, clinical diagnoses and causal variants in the cohort with 48 novel variants in 21 genes. We summarize scientific contributions of the center to the description of clinical and mutation profiles and discovery of new phenotypes and genetic etiology. Our study illustrates the establishment and application of genomic testing tools for genetic disorders of skeleton in a large cohort. We believe this could be a model to emulate for other developing genetic centers.

An association study of dopaminergic (DRD2) and serotoninergic (5-HT2) gene polymorphism and schizophrenia in a North Indian population

The aim of this study was to investigate whether single nucleotide polymorphisms (SNPs) in DRD2 and 5-HT2 receptor genes are associated with schizophrenia in North Indian population. Four hundred forty-three patients who met ICD10-DCR criteria for schizophrenia were enrolled from six participating centers along with 443 genetically related healthy subjects and 150 genetically unrelated healthy participants. A total of 7 gene polymorphisms from DRD2 (rs1800497, rs1079597, rs1800498, rs1801028) and 5-HT2 A (rs6313, rs6311, rs6305) were genotyped for their association with schizophrenia. No significant difference was found in frequency of various genotypes and alleles of the studied markers for DRD2 and 5-HT2 A genes between the cases and their genetic controls. However, significant differences were noted for rs1079597 genotype (Taq1B; p = 0.039) and its allele frequencies (p = 0.029) in persons with schizophrenia and the unrelated healthy controls. The DRD2 (Taq1 A-B-D) and 5-HT2 A (rs6311-rs6313-rs6305) haplotype frequencies differed significantly for A2B1D2 [p = 0.038; OR = 0.685 (95%CI = 0.479-0.981)] and ACC [p = 0.001; OR = 0.621 (95%CI = 0.461-0.838)] for the cases vs genetically related healthy controls. Similarly, significant difference was observed for the frequencies of GCC [p = 0.006; OR = 0.692 (95%CI = 0.532-0.900)] and ACC [p < 0.001; OR = 3.622 (95%CI = 1.73-7.585)] in the cases and unrelated healthy controls. Unlike previous research from India as well as abroad, the predominance of B1 allele of rs1079597 in patients with schizophrenia and absence of Cys311 in all study participants is a salient difference. Concluding, the B2 allele of rs1079597 may increase the risk of schizophrenia while the A2B1D2 haplotype may be protective in North Indian population.

High mortality due to congenital malformations in children aged < 1 year in French Guiana

BACKGROUND

In French Guiana, pregnant women may be exposed to infectious, environmental, and social risks leading to congenital malformation. The objective of the study was to study mortality rates from congenital malformations among infants < 1 year and to compare them with those in mainland France.

METHODS

We used the CEPI DC (INSERM) database, which compiles annual data from death certificates in all French territories using the International Classification of Diseases. Annual deaths for French Guiana and mainland France between 2005 and 2015 were compiled. The age category studied was children less than 1 year and deaths from congenital malformations, deformations and chromosomal abnormalities were compiled. Crude risk ratios and 95% confidence intervals were calculated to quantify the excess risk of disease in French Guiana.

RESULTS

In French Guiana between 2005 and 2015 there were 666 deaths of children aged < 1 year, among which, 132 (19.8%) were due to congenital malformations and chromosomal anomalies. Overall the risk ratio of death from congenital malformations and chromosomal anomalies between French Guiana and mainland France was 2.7 (1.5-4.7), P < 0.001 for neurological congenital malformations it was 4.8 (1.2-19.7), P = 0.01 and for congenital malformations of the circulatory system it was 3.3 (1.5-6.9), P = 0.001.

CONCLUSIONS

The incidence of death from congenital malformations or chromosomal anomalies in French Guiana was significantly higher than in mainland France. Explanations for this may be infections, genetic causes, nutritional causes, and toxic causes that are prevalent. There is a need to identify factors that predispose children born in French Guiana to having a higher risk of congenital malformations and chromosomal anomalies.

Contribution of Inbred Singletons to Variance Component Estimation of Heritability and Linkage

OBJECTIVES

An interesting consequence of consanguinity is that the inbred singleton becomes informative for genetic variance. We determine the contribution of an inbred singleton to variance component analysis of heritability and linkage.

METHODS

Statistical theory for the power of variance component analysis of quantitative traits is used to determine the expected contribution of an inbred singleton to likelihood-ratio tests of heritability and linkage.

RESULTS

In variance component models, an inbred singleton contributes relatively little to a test of heritability but can contribute substantively to a test of linkage. For small-to-moderate quantitative trait locus (QTL) effects and a level of inbreeding comparable to matings between first cousins (the preferred form of union in many human populations), an inbred singleton can carry nearly 25% of the information of a non-inbred sib pair. In more highly inbred contexts available with experimental animal populations, nonhuman primate colonies, and some human subpopulations, the contribution of an inbred singleton relative to a sib pair can exceed 50%.

CONCLUSIONS

Inbred individuals, even in isolation from other members of a sample, can contribute to variance component estimation and tests of heritability and linkage. Under certain conditions, the informativeness of the inbred singleton can approach that of a non-inbred sib pair.

A review of the reproductive consequences of consanguinity

BACKGROUND

Consanguinity is the close union, sexual relationship or marriage between persons who have common biological ancestors usually up to about 2nd cousins. Contrary to general opinion consanguinity is quite common and is practiced worldwide. It is an important topic as while rates of consanguineous unions in certain society have decreased over time, rates have remained stable or increased in other societies with rates as high as 80.6% in some communities. Our aim was to conduct a review looking at general aspects of consanguinity and any published reproductive outcomes in literature. We also looked at possible future directions that could be relevant in the management of the consanguineous couple to help improve reproductive outcomes.

METHOD

We conducted a PUBMED, CINAHL, Web of Knowledge and Google Scholar search looking at articles on consanguinity. Consanguinity articles related to pregnancy and reproduction were searched using additional filters looking at our specific areas of interest. All relevant publications up to March 2015 were reviewed. Additional search for relevant articles pertaining to pre implantation genetic diagnosis for future directions in the management of the consanguineous couple was done. Most publications were found in books, on line articles and journals. Most were retrospective, population or cohort studies.

RESULT

Consanguinity is practiced by up to 10% of the world's population with rates ranging from 80.6% in certain provinces in the Middle East to less than 1% in western societies. It predates Islam and has been practiced since Old Testament times. The most commonly cited reason for consanguinity is sociocultural and socioeconomic although it is also more common in certain religions. In areas where rates of Consanguinity are reducing urban migration and increasing education rates are thought to be contributory. Congenital malformations have long been established to be higher in consanguineous couples above the background rate (4.5% Vs 1%).Due to "Founder effect" or a common ancestor, Consanguinity is most commonly associated with Inborn errors of metabolism most of which are autosomal recessive. Consanguinity increases the incidence of multifactorial disorders such as diabetes, cardiovascular disorders, obesity and certain types of cancers. These may in turn affect reproductive outcomes. It may also affect fertility rates. Pregnancy outcomes like increased pregnancy wastages and preterm labor have been reported with consanguinity. Other studies produced conflicting evidence on its effect regarding outcomes like hypertensive disorders of pregnancy and Intrauterine growth restriction.

CONCLUSION

Consanguinity continues to be practiced worldwide and in some countries rates are increasing. The main reason for the practice appears to be sociocultural and socioeconomic although religious beliefs is a contributory factor. The most significant effects on reproductive outcomes are mostly due to autosomal recessive inherited conditions and inborn errors of metabolism. It also significantly increases the inheritance of certain multifactorial disorders like diabetes which may indirectly affect reproductive outcomes. In the future with the completion of the study of the whole human Genome and current advances in Pre implantation Genetic diagnosis and screening it may be possible to mitigate some of the adverse reproductive outcomes associated with consanguinity.

Hybrid marriages and phenotypic heterosis in offspring: Evidence from China

In genetics, heterosis refers to the phenomenon that cross-breeding within species leads to offspring that are genetically fitter than their parents and exhibit improved phenotypic characteristics. Based on the theory of heterosis and existing genetic evidence, offspring of "hybrid" marriages (spouses originating from different states/provinces/countries/areas), though relatively rare due to physical boundaries, may exhibit greater genetic fitness in terms of intelligence, height, or physical attractiveness (the "distance-performance" hypothesis). This study explores whether heterosis is a contributing factor to offspring's educational attainment in China by applying a high-dimensional fixed effects (HDFE) modelling framework to the unique 0.1% micro-sample of the 2000 Chinese Population Census data. Concerning potential endogeneity of hybrid marriages, we conduct a series of robustness checks. Reassuringly, the estimated heterosis effect remains significantly positive across various measurements, after controlling for parental educational attainments/height, environmental influences, and over a thousand region and region-by-year fixed effects. The effects in male and higher-educated offspring are found to be stronger. Results are replicated when analyzing body height using data from the China Health and Nutrition Survey. Although endogeneity of "hybrid marriages" may not be completely ruled out, the current study sheds light on the potentially beneficial effects of interprovincial migration on population-level human capital accumulation, and we hope that this paper can intrigue future studies that further address endogeneity. The implied heterosis effect could, therefore, be profound for Homo sapiens as a species from an evolutionary point of view. An additional important implication is that the overall genetic influences of parents on offspring's performance may be further decomposed into a conventional heredity effect and a heterosis effect that has been neglected previously.

A comprehensive screening program for β-thalassemia and other hemoglobinopathies in the Hooghly District of West Bengal, India, dealing with 21 137 cases

We here present a report of population screening programs (January 2012-December 2015) conducted by the Thalassemia Control Unit, Imambara Sadar Hospital, Chinsurah, Hooghly in the Hooghly District of West Bengal, India for prevention of thalassemia. We screened β-thalassemia (β-thal) heterozygotes and homozygotes, and Hb E (HBB: c.79G > A)-β-thal compound heterozygotes. Among 21 137 cases, we found 1968 heterozygotes and 192 homozygotes or compound heterozygotes. Results were evaluated with standard hematological analyses including red cell indices, hemoglobin (Hb) typing and quantification. The participants of the screening program were divided into six groups (children, pre-marriage cases, post-marital cases, family members of affected individuals, family members of carriers and pregnant women). While considering the average frequency of carriers, many reports recorded both related individuals (family members of trait and affected individuals) as well as unrelated individuals such as school children and pregnant women. These would have to be considered separately and only the unrelated individuals taken to estimate carrier frequencies in this article that would give more realistic data on carrier frequency of unrelated individuals.

Parenteral exposure to pesticides and occurence of congenital malformations: hospital-based case-control study

Background

Most fetal defects are associated with genetic and environmental causes, among them, exposure of pregnant women to intensive pesticide use. Agribusiness is the economic basis of the state of Mato Grosso, the largest consumer of pesticides of all Brazilian states. The objective of this study was to investigate the association between past parental exposure to pesticides and the occurrence of congenital malformations in children in Mato Grosso, Brazil.

Methods

This hospital-based case–control study was conducted in Cuiabá, the capital of Mato Grosso, from March to October 2011. Data was collected in all public, private, and health plan referral hospitals that provide care for pregnant women in the state of Mato Grosso and were situated in Cuiabá. Cases were children under 5 years of age with congenital malformations classified in Chapter XVIII of the International Classification of Diseases-10 and controls were children within the same age range, without congenital malformations, treated at the same hospitals. Malformation-related data was obtained from the patients’ medical records. Socioeconomic data and information about parental exposure to pesticides were obtained in an interview with the mother using a standardized questionnaire. We conducted multivariate logistic regression to assess the relation between parent report of past pesticide use and congenital malformations. We also assessed effect modification to verify whether low maternal education level modified the association between exposure and our outcome.

Results

We observed positive effect modification of the association of paternal past exposure to pesticide and congenital malformation in the offspring by maternal education for mothers with low educational level (OR = 8.40, 95 % CI 2.17–32.52), father’s work related to farming (OR = 4.65, 95 % CI 1.03–20.98) and paternal past exposure to pesticides (OR = 4.15, 95 % CI 1.24–13.66).

Conclusion

These findings provide further evidence that paternal exposure to pesticides, especially when associated with a low maternal education level, may be related to higher rates of fetal malformation in Mato Grosso, Brazil.

Seventeen Novel Mutations in PCCA and PCCB Genes in Indian Propionic Acidemia Patients, and Their Outcomes

AIMS

The goal of this study was to identify mutations in the propionyl-CoA carboxylase alpha subunit (PCCA) and propionyl-CoA carboxylase beta subunit (PCCB) genes, and to assess their effects on propionic academia (PA) patients.

METHODOLOGY

Twenty-five Indian children with PA were enrolled in this study. Bidirectional Sanger sequencing was performed on both the coding and flanking regions of the PCCA and PCCB genes and the chromatograms were analyzed. Bioinformatic tools were used to classify novel variations into pathogenic or benign.

RESULTS

The majority of the cases (19/25, 76%) were of the early-onset (<90 days of age) type and 5 were of the late-onset type. The majority of patients had mutations in the PCCA gene (18/25). A total of 26 mutations were noted: 20 in the PCCA gene and 6 in PCCB gene. Seventeen mutations were novel (14 in PCCA and 3 in PCCB). The SNP c.937C>T (p.Arg313Ter), was noted in 9/36 (25%) alleles in the PCCA gene. All of the children were symptomatic and only three survived who are doing well with no major disabilities.

CONCLUSION

The spectrum of mutations in the PCCA and PCCB genes among Indians is distinct from other populations. The absence of a common mutation signifies the heterogeneity and admixture of various subpopulations. These findings also suggest that individuals of Indian origin may not benefit from the mutation-based "carrier screening panels" offered by many genetic laboratories.

Estimation of inbreeding and substructure levels in African-derived Brazilian quilombo populations

This article deals with the estimation of inbreeding and substructure levels in a set of 10 (later regrouped as eight) African-derived quilombo communities from the Ribeira River Valley in the southern portion of the state of São Paulo, Brazil. Inbreeding levels were assessed through F-values estimated from the direct analysis of genealogical data and from the statistical analysis of a large set of 30 molecular markers. The levels of population substructure found were modest, as was the degree of inbreeding: in the set of all communities considered together, F-values were 0.00136 and 0.00248 when using raw and corrected data from their complete genealogical structures, respectively, and 0.022 and 0.036 when using the information taken from the statistical analysis of all 30 loci and of 14 single-nucleotide polymorphic loci, respectively. The overall frequency of consanguineous marriages in the set of all communities considered together was ∼ 2%. Although modest, the values of the estimated parameters are much larger than those obtained for the overall Brazilian population and in general much smaller than the ones recorded for other Brazilian isolates. To circumvent problems related to heterogeneous sampling and virtual absence of reliable records of biological relationships, we had to develop or adapt several methods for making valid estimates of the prescribed parameters.

Genetic testing and genomic analysis: a debate on ethical, social and legal issues in the Arab world with a focus on Qatar

In 2013 both Saudi Arabia and Qatar launched genome projects with the aim of providing information for better diagnosis, treatment and prevention of diseases and, ultimately to realize personalized medicine by sequencing hundred thousands samples. These population based genome activities raise a series of relevant ethical, legal and social issues general, related to the specific population structure as well as to the Islamic perspective on genomic analysis and genetic testing. To contribute to the debate, the Authors after reviewing the existing literature and taking advantage of their professional experience in the field and in the geographic area, discuss and provide their opinions. In particular, the Authors focus on the impact of consanguinity on population structure and disease frequency in the Arab world, on genetic testing and genomic analysis (i.e. technical aspects, impact, etc.) and on their regulations. A comparison between the Islamic perspective and the ethical, social and legal issues raised in other population contexts is also carried. In conclusion, this opinion article with an up-to-date contribution to the discussion on the relevance and impact of genomic analysis and genetic testing in the Arab world, might help in producing specific national guidelines on genetic testing and genomic analysis and help accelerate the implementation and roll out of genome projects in Muslim countries and more specifically in Qatar, and other countries of the Gulf.

Profiling β Thalassemia Mutations in Consanguinity and Nonconsanguinity for Prenatal Screening and Awareness Programme

Mutation spectrum varies significantly in different parts and different ethnic groups of India. Social factors such as preference to marry within the community and among 1st degree relatives (consanguinity) play an important role in impeding the gene pool of the disease within the community and so in society by and large. The present paper discusses the role of consanguinity in profiling of beta thalassemia mutation, and thus the approach for prenatal screening and prevention based awareness programme. Clinically diagnosed 516 cases of beta thalassemia were screened at molecular level. A detailed clinical Proforma was recorded with the information of origin of the family, ethnicity, and consanguinity. The present study reports that subjects originating from Uttar Pradesh, Uttarakhand, Bihar, and Jharkhand have c.92+5G>C and c.124_127delTTCT mutation as the commonest mutation compared to the subjects hailing from Madhya Pradesh and Chhattisgarh and Nepal where sickle mutation was found more common. In 40 consanguineous unions more common and specific beta mutations with higher rate of homozygosity have been reported. This consanguinity-based data helps not only in deciding target oriented prenatal diagnostic strategies but also in objective based awareness programmes in prevention of thalassemia major birth.

Mutations in ARSB in MPS VI patients in India

Mucopolysaccharidosis VI (MPS VI) is an autosomal recessive inborn error of metabolism caused by mutations in the arylsulfatase B gene (ARSB) and consequent deficient activity of ARSB, a lysosomal enzyme. We present here the results of a study undertaken to identify the mutations in ARSB in MPS VI patients in India. Around 160 ARSB mutations, of which just 4 are from India, have been reported in the literature. Our study covered nine MPS VI patients from eight families. Both familial mutations were found in seven families, and only one mutation was found in one family. Seven mutations were found - four novel (p.G38_G40del3, p.C91R, p.L98R and p.R315P), two previously reported from India (p.D53N and p.W450C), and one reported from outside India (p.R160Q). One mutation, p.W450C, was present in two families, and the other six mutations were present in one family each. Analysis of the molecular structure of the enzyme revealed that most of these mutations either cause loss of an active site residue or destabilize the structure of the enzyme. The only previous study on mutations in ARSB in Indian MPS VI patients, by Kantaputra et al. 2014 [1], reported four novel mutations of which two (p.D53N and p.W450C) were found in our study as well. Till date, nine mutations have been reported from India, through our study and the Kantaputra study. Eight out of these nine mutations have been found only in India. This suggests that the population studied by us might have its own typical set of mutations, with other populations equally likely to have their own set of mutations.

Origin and dynamics of admixture in Brazilians and its effect on the pattern of deleterious mutations

While South Americans are underrepresented in human genomic diversity studies, Brazil has been a classical model for population genetics studies on admixture. We present the results of the EPIGEN Brazil Initiative, the most comprehensive up-to-date genomic analysis of any Latin-American population. A population-based genome-wide analysis of 6,487 individuals was performed in the context of worldwide genomic diversity to elucidate how ancestry, kinship, and inbreeding interact in three populations with different histories from the Northeast (African ancestry: 50%), Southeast, and South (both with European ancestry >70%) of Brazil. We showed that ancestry-positive assortative mating permeated Brazilian history. We traced European ancestry in the Southeast/South to a wider European/Middle Eastern region with respect to the Northeast, where ancestry seems restricted to Iberia. By developing an approximate Bayesian computation framework, we infer more recent European immigration to the Southeast/South than to the Northeast. Also, the observed low Native-American ancestry (6-8%) was mostly introduced in different regions of Brazil soon after the European Conquest. We broadened our understanding of the African diaspora, the major destination of which was Brazil, by revealing that Brazilians display two within-Africa ancestry components: one associated with non-Bantu/western Africans (more evident in the Northeast and African Americans) and one associated with Bantu/eastern Africans (more present in the Southeast/South). Furthermore, the whole-genome analysis of 30 individuals (42-fold deep coverage) shows that continental admixture rather than local post-Columbian history is the main and complex determinant of the individual amount of deleterious genotypes.

Identification of the hot-spot areas for sickle cell disease using cord blood screening at a district hospital: an Indian perspective

Sickle cell disease (SCD), a genetic disorder often reported late, can be identified early in life, and hot-spot areas may be identified to conduct genetic epidemiology studies. This study was undertaken to estimate prevalence and to identify hot spot area for SCD in Kalahandi district, by screening cord blood of neonates delivered at the district hospital as first-hand information. Kalahandi District Hospital selected for the study is predominated by tribal population with higher prevalence of SCD as compared to other parts of Odisha. Cord blood screening of SCD was carried out on 761 newborn samples of which 13 were screened to be homozygous for SCD. Information on area of parent's residence was also collected. Madanpur Rampur area was found to be with the highest prevalence of SCD (10.52 %) and the gene distribution did not follow Hardy-Weinberg Equation indicating un-natural selection. The approach of conducting neonatal screening in a district hospital for identification of SCD is feasible and appropriate for prioritizing area for the implementation of large-scale screening and planning control measures thereof.

Mutational spectrum of thalassemias and other hemoglobinopathies in West Bengal, Eastern India

Thalassemia, an autosomal recessive blood disease, shows a variety of clinical expression in terms of asymptomatic to severe blood transfusion dependence. More than 500 alleles have been characterized in or around the β-globin region. Most of the geographical regions have their own characteristic alleles that predominantly circulate within the communities present in that particular region. In this article, we try to throw some light to explore the spectrum of β-thalassemia (β-thal) alleles present in West Bengal, the eastern part of India. This study comprises thalassemia carriers and diseased persons from different districts of West Bengal. We not only explored the complete mutational spectrum of this state but we also tried to fix the critical range of the values of different hematological parameters [Hb A2, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH)] for the heterozygotes or carriers of β-thal with the same mutational background. At the same time, we also tried to evaluate the maximum weighted frequency of these parameters for the heterozygotes or carriers of β-thal with the same mutational background, so that by observing these cut-off values of standard hematological parameters, we were able to predict the carrier or diseased status for mass scale screening and also try to correlate the values of these parameters with different combinations of β-thal mutation-specific alleles that can be more informative in mass scale (carrier) screening.

Health problems, complex life, and consanguinity among ethnic minority Muslim women in Nepal

BACKGROUND

Marriage between blood relatives is common among Muslim ethnic minority population in Nepal. Albeit, the adverse effects of such a consanguineous marriage on health are controversial.

OBJECTIVE

To determine the prevalence, characteristics and health outcomes related to consanguineous marriage.

DESIGN

A cross-sectional survey was carried out using a cluster sampling technique to select the respondents. A total of 400 women aged 15-49 years were interviewed from September 2011 to February 2012. A structured questionnaire was administered through face-to-face meetings. Adjusted odds ratios (AOR) were estimated by a stepwise likelihood ratio method with binary logistic regression.

RESULTS

The overall prevalence of consanguinity was 36.7%. The median age at marriage and age at first childbirth was 15 and 18 years, respectively. The association of being in a consanguineous marriage among women whose husband's education level were secondary or higher was 3.35 (95% CI 1.56, 7.12) times greater than among those whose husbands were unable to read and write. Woman who have consanguineous marriage were less likely to have (AOR 0.46, 95% CI 0.26, 0.82) used contraceptive than those who have non-consanguineous marriage. Women who have consanguineous marriage were more (AOR 1.80; 95% CI 0.90, 3.61) likely to have birth defect in their children than those who have non-consanguineous marriage. The association of having a history of death after live birth among women who experienced emotional violence was 2.60 (95% CI 1.36, 5.00) and physical violence 2.15 (95% CI 1.16, 3.93) times greater than among those who did not experience violence.

CONCLUSIONS

Several factors like husband's education and dowry practices are associated with consanguineous marriage. Further, these factors including consanguineous marriage and marital violence are also accountable for negative health consequences. Thus, multicomponent interventions are needed in order to improve the health condition of Nepalese Muslim community in rural area.

The relative frequency of lysosomal storage disorders: a medical genetics referral laboratory's experience from India

Lysosomal storage disorders are a group of rare, genetically inherited metabolic disorders. Because the literature on epidemiologic data is scanty from India, we attempted to determine their relative frequency and regional distribution. Our retrospective study included 1558 patients with clinical suspicion of various lysosomal storage disorders referred to Sandor Lifesciences Pvt Ltd during 2007 to 2012. About 30% of the cases were tested positive, with sphingolipidoses as the most common subgroup, followed by mucopolysaccharidoses, and Gaucher disease as the most frequently occurring individual lysosomal storage disorder. Our data indicates that lysosomal storage disorders are more common in males than females and infants comprise the most common age group followed by juvenile. The burden of these disorders is predicted to be high in India because of the large population, coupled with the practice of consanguineous marriages. This study emphasizes the importance of epidemiologic studies in order to implement appropriate preventive measures.

Population based family history analysis of Brahmins in a small town in India for the prevalence of type-2 diabetes mellitus

OBJECTIVES:

The objective of this study is to determine the inheritance pattern of type-2 diabetes and make stratification for the general population risk.

MATERIALS AND METHODS:

A questionnaire was developed for o btaining the family history. Analysis of the data was carried out by using student and Chi-square tests and for stratification; the guidelines of Scheuner et al. were followed.

RESULTS:

The pattern of inheritance is the male sex specific (χ² =13.44). The mean age of onset of diabetes in parents was 58.61 ± 2.94 and in offspring 46.75 ± 2.54. In all 47.22 ± 11.53% families were found in high risk and 31.94 ± 10.77% in the moderate risk category. In female diabetics, the onset was in the age range of 41-60 years.

CONCLUSION:

We found a high-risk of diabetes and familial clustering in successive generations of Brahmins with prominent male sex specificity. In females onset of diabetes was coinciding with the period around menopause.

Hereditary ectodermal dysplasia: A retrospective study

Background:

Ectodermal dysplasia (ED) is a group of rare, inherited disorders characterized by sparse hair, missing teeth and inability to sweat.

Objective:

To review and analyze cases of ED with an emphasis on clinical manifestations and parent's marriage history.

Methodology:

The present retrospective study was conducted by assessing the clinical records of nineteen cases of ED, available in the archives of the department; for age, gender, family history of consanguineous marriage and clinical manifestations.

Results:

It was observed that ED was more prevalent in males, with a ratio of 1.7:1. The hypohydrotic type was more common (78.95%) than hydrotic type (21.05%). The marriage history of parents revealed that 66.67% had consanguineous marriage and had 68.42% offspring's affected with ED; whereas 33.33% had history of non-consanguineous marriage and had 31.58% offspring's affected with ED. The clinical manifestations observed were- dry skin(94.74%); scaly skin(42.11%); sparse hair on scalp, eyebrows and eyelashes(100%); frontal bossing(63.18%); saddle nose (57.89%); hypertelorism (47.37%); nail abnormality(52.63%); normal sweat glands(21.05%); abnormal sweat glands(78.95%); hypoplastic maxilla(52.63%); protuberant lips (57.89%); palmo-plantar keratosis(21.05%); wrinkled & hyper pigmented facial skin(84.21%); partial anodontia(94.74%); conical shaped teeth(84.21%); high arched palate(68.42%); thin alveolar bone(100.00%); taurodontism(21.05%) and cleft lip & cleft palate(05.26%). The number of teeth present in all the cases ranged from 0 to 19.

Conclusion:

ED patients suffer from social problems and poor psychological and physiological development as a result of unacceptable esthetics and abnormal function of orofacial structures. Oral rehabilitation thus becomes mandatory, although it is often difficult; particularly in pediatric patients.