218 research outputs found

    Comprehensive genotype‐phenotype correlation in AP‐4 deficiency syndrome; Adding data from a large cohort of Iranian patients

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    Mutations in adaptor protein complex‐4 (AP‐4) genes have first been identified in 2009, causing a phenotype termed as AP‐4 deficiency syndrome. Since then several patients with overlapping phenotypes, comprised of intellectual disability (ID) and spastic tetraplegia have been reported. To delineate the genotype‐phenotype correlation of the AP‐4 deficiency syndrome, we add the data from 30 affected individuals from 12 out of 640 Iranian families with ID in whom we detected disease‐causing variants in AP‐4 complex subunits, using next‐generation sequencing. Furthermore, by comparing genotype‐phenotype findings of those affected individuals with previously reported patients, we further refine the genotype‐phenotype correlation in this syndrome. The most frequent reported clinical findings in the 101 cases consist of ID and/or global developmental delay (97%), speech disorders (92.1%), inability to walk (90.1%), spasticity (77.2%), and microcephaly (75.2%). Spastic tetraplegia has been reported in 72.3% of the investigated patients. The major brain imaging findings are abnormal corpus callosum morphology (63.4%) followed by ventriculomegaly (44.5%). Our result might suggest the AP‐4 deficiency syndrome as a major differential diagnostic for unknown hereditary neurodegenerative disorders

    Mutation analysis of BRCA1 and BRCA2 genes in Iranian high risk breast cancer families

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    Background: Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell division and maintains chromosomal stability leading to cellular immortalization. Telomerase has been associated with negative prognostic indicators in some studies. The present study aims to detect any association between telomerase sub-units: hTERT and hTR and the prognostic indicators including tumour's size and grade, nodal status and patient's age. Methods: Tumour samples from 46 patients with primary invasive breast cancer and 3 patients with benign tumours were collected. RT-PCR analysis was used for the detection of hTR, hTERT, and PGM1 (as a housekeeping) genes expression. Results: The expression of hTR and hTERT was found in 31(67.4%) and 38 (82.6%) samples respectively. We observed a significant association between hTR gene expression and younger age at diagnosis (p = 0.019) when comparing patients ≤ 40 years with those who are older than 40 years. None of the benign tumours expressed hTR gene. However, the expression of hTERT gene was revealed in 2 samples. No significant association between hTR and hTERT expression and tumour's grade, stage and nodal status was seen. Conclusion: The expression of hTR and hTERT seems to be independent of tumour's stage. hTR expression probably plays a greater role in mammary tumourogenesis in younger women (≤ 40 years) and this may have therapeutic implications in the context of hTR targeting strategies

    Sexuality, rights and personhood: tensions in a transnational world

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    <p>Abstract</p> <p>Background</p> <p>This article discusses what happens when normative ‘global’ discourses of rights and individuated sexual identity confront the messiness of ‘local’ realities. It considers the tensions that emerge when the relationship between sexual and social identities is not obvious and the implications of such tensions for public health and sexual rights activism. These questions are addressed through debates over the naming of male-to-male sexualities and desires in the context of globalization and the growth of a large NGO (non-governmental organization) sector in urban Bangladesh.</p> <p>Methods</p> <p>The material in the paper draws on a research project undertaken in 2008-9 in Dhaka, Bangladesh. A fundamental objective was to produce a contextualized understanding of sexuality in Dhaka city. Methods used included structured interviews, focus group discussions and informal conversations with a range of participants (students, factory workers, public health professionals and sexual minorities). The aim was to generate a conceptual and analytical framework around sexuality and rights rather than to undertake an empirical survey of any one population.</p> <p>Results</p> <p>As descriptors, globalized identity categories such as Men who have Sex with Men (MSM), used by public health providers, the state and donors; and gay/lesbian, invoked by human rights activists and transnational NGOs, are too narrow to capture the fluid and highly context-specific ways in which gender and sexually nonconforming persons understand themselves in Bangladesh. Further, class position mediates to a significant degree the reception, appropriation or rejection of transnational categories such as MSM and Lesbian, Gay, Bisexual, Transgender (LGBT). The tension is reflected in the sometimes fraught relations between service providers to MSM, the people they serve and an emerging group who identify as LGBT.</p> <p>Conclusion</p> <p>A simple politics of recognition will be inadequate to the task of promoting health and human rights for all; such a strategy would effectively exclude individuals who do not necessarily connect their sexual practices with a specific sexual or social identity.</p

    J. Med. Genet.

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    Background: Primary microcephaly (MCPH) is a genetically heterogeneous disorder showing an autosomal recessive mode of inheritance. Affected individuals present with head circumferences more than three SDs below the age- and sex-matched population mean, associated with mild to severe mental retardation. Five genes (MCPH1, CDK5RAP2, ASPM, CENPJ, STIL) and two genomic loci, MCPH2 and MCPH4, have been identified so far. Methods and results: In this study, we investigated all seven MCPH loci in patients with primary microcephaly from 112 Consanguineous Iranian families. In addition to a thorough clinical characterisation, karyotype analyses were performed for all patients. For Homozygosity mapping, microsatellite markers were selected for each locus and used for genotyping. Our investigation enabled us to detect homozygosity at MCPH1 (Microcephalin) in eight families, at MCPH5 (ASPM) in thirtheen families. Three families showed homozygosity at MCPH2 and five at MCPH6 (CENPJ), and two families were linked to MCPH7 (STIL). The remaining 81 families were not linked to any of the seven known loci. Subsequent sequencing revealed eight, 10 and one novel mutations in Microcephalin, ASPM and CENPJ, respectively. In some families, additional features such as short stature, seizures or congenital hearing loss were observed in the microcephalic patient, which widens the spectrum of clinical manifestations of mutations in known microcephaly genes. Conclusion: Our results show that the molecular basis of microcephaly is heterogeneous; thus, the Iranian population may provide a unique source for the identification of further genes underlying this disorder

    Iranome: A catalogue of genomic variations in the Iranian population

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    Considering the application of human genome variation databases in precision medicine, population-specific genome projects are continuously being developed. However, the Middle Eastern population is underrepresented in current databases. Accordingly, we established Iranome database (www.iranome.com) by performing whole exome sequencing on 800 individuals from eight major Iranian ethnic groups representing the second largest population of Middle East. We identified 1,575,702 variants of which 308,311 were novel (19.6%). Also, by presenting higher frequency for 37,384 novel or known rare variants, Iranome database can improve the power of molecular diagnosis. Moreover, attainable clinical information makes this database a good resource for classifying pathogenicity of rare variants. Principal components analysis indicated that, apart from Iranian-Baluchs, Iranian-Turkmen, and Iranian-Persian Gulf Islanders, who form their own clusters, rest of the population were genetically linked, forming a super-population. Furthermore, only 0.6% of novel variants showed counterparts in "Greater Middle East Variome Project", emphasizing the value of Iranome at national level by releasing a comprehensive catalog of Iranian genomic variations and also filling another gap in the catalog of human genome variations at international level. We introduce Iranome as a resource which may also be applicable in other countries located in neighboring regions historically called Greater Iran (Persia)

    BOD1 Is Required for Cognitive Function in Humans and <i>Drosophila</i>

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    Here we report a stop-mutation in the BOD1 (Biorientation Defective 1) gene, which co-segregates with intellectual disability in a large consanguineous family, where individuals that are homozygous for the mutation have no detectable BOD1 mRNA or protein. The BOD1 protein is required for proper chromosome segregation, regulating phosphorylation of PLK1 substrates by modulating Protein Phosphatase 2A (PP2A) activity during mitosis. We report that fibroblast cell lines derived from homozygous BOD1 mutation carriers show aberrant localisation of the cell cycle kinase PLK1 and its phosphatase PP2A at mitotic kinetochores. However, in contrast to the mitotic arrest observed in BOD1-siRNA treated HeLa cells, patient-derived cells progressed through mitosis with no apparent segregation defects but at an accelerated rate compared to controls. The relatively normal cell cycle progression observed in cultured cells is in line with the absence of gross structural brain abnormalities in the affected individuals. Moreover, we found that in normal adult brain tissues BOD1 expression is maintained at considerable levels, in contrast to PLK1 expression, and provide evidence for synaptic localization of Bod1 in murine neurons. These observations suggest that BOD1 plays a cell cycle-independent role in the nervous system. To address this possibility, we established two Drosophila models, where neuron-specific knockdown of BOD1 caused pronounced learning deficits and significant abnormalities in synapse morphology. Together our results reveal novel postmitotic functions of BOD1 as well as pathogenic mechanisms that strongly support a causative role of BOD1 deficiency in the aetiology of intellectual disability. Moreover, by demonstrating its requirement for cognitive function in humans and Drosophila we provide evidence for a conserved role of BOD1 in the development and maintenance of cognitive features

    Interpreting the role of de novo protein-coding mutations in neuropsychiatric disease

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    Pedigree, linkage and association studies are consistent with heritable variation for complex disease due to the segregation of genetic factors in families and in the population. In contrast, de novo mutations make only minor contributions to heritability estimates for complex traits. Nonetheless, some de novo variants are known to be important in disease etiology. The identification of risk-conferring de novo variants will contribute to the discovery of etiologically relevant genes and pathways and may help in genetic counseling. There is considerable interest in the role of such mutations in complex neuropsychiatric disease, largely driven by new genotyping and sequencing technologies. An important role for large de novo copy number variations has been established. Recently, whole-exome sequencing has been used to extend the investigation of de novo variation to point mutations in protein-coding regions. Here, we consider several challenges for the interpretation of such mutations in the context of their role in neuropsychiatric disease

    Investigation of chromosomal abnormalities and microdeletion/ microduplication(s) in fifty Iranian patients with multiple congenital anomalies

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    Objective: Major birth defects are inborn structural or functional anomalies with long-term disability and adverse impacts on individuals, families, health-care systems, and societies. Approximately 20 of birth defects are due to chromosomal and genetic conditions. Inspired by the fact that neonatal deaths are caused by birth defects in about 20 and 10 of cases in Iran and worldwide respectively, we conducted the present study to unravel the role of chromosome abnormalities, including microdeletion/microduplication(s), in multiple congenital abnormalities in a number of Iranian patients. Materials and Methods: In this descriptive cross-sectional study, 50 sporadic patients with Multiple Congenital Anomalies (MCA) were selected. The techniques employed included conventional karyotyping, fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA), and array comparative genomic hybridisation (array-CGH), according to the clinical diagnosis for each patient. Results: Chromosomal abnormalities and microdeletion/microduplication(s) were observed in eight out of fifty patients (16). The abnormalities proved to result from the imbalances in chromosomes 1, 3, 12, and 18 in four of the patients. However, the other four patients were diagnosed to suffer from the known microdeletions of 22q11.21, 16p13.3, 5q35.3, and 7q11.23. Conclusion: In the present study, we report a patient with 46,XY, der(18)12/46,XY, der(18), +mar8 dn presented with MCA associated with hypogammaglobulinemia. Given the patient�s seemingly rare and highly complex chromosomal abnormality and the lack of any concise mechanism presented in the literature to justify the case, we hereby propose a novel mechanism for the formation of both derivative and ring chromosome 18. In addition, we introduce a new 12q abnormality and a novel association of an Xp22.33 duplication with 1q43q44 deletion syndrome. The phenotype analysis of the patients with chromosome abnormality would be beneficial for further phenotype-genotype correlation studies. © 2019 Royan Institute (ACECR). All rights reserved
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