Investigation of mutations in exons 19-23 MYH7 gene in hypertrophic cardiomyopathy patients using PCR-SSCP/HA technique in Chaharmahal va Bakhtiari province

زمینه و هدف: کاردیومایوپاتی هایپرتروفی (HCM) رایج ترین نوع از بیماری های قلبی است که 2/0 درصد از جمعیت جهان را تحت تأثیر قرار داده و همچنین رایج ترین علت مرگ قلبی ناگهانی در جوانان زیر 35 سال است. حدود 35 درصد موارد بیماری مربوط به اگزون های 24- 8 از ژن MYH7 است. هدف این مطالعه بررسی احتمال حضور جهش های مربوط به ژن MYH7 در اگزون های 23-19 در بیماران HCM استان چهارمحال و بختیاری بود. روش بررسی: در این مطالعه تجربی 30 بیمار مبتلا به HCM به روش نمونه گیری آسان از بین مراجعین به کلینیک قلب دانشگاه علوم پزشکی شهرکرد انتخاب شدند. در این بیماران DNAبه روش استاندارد فنل-کلروفرم استخراج شد. اگزون های مورد نظر با استفاده از روش PCR تکثیر و با روش SSCP به صورت تک رشته تبدیل شد و همراه نمونه های دو رشته ای روی ژل پلی آکریل آمید الکتروفورز گردید. سپس باندهای مشکوک تعیین توالی گردید و نتایج با استفاده از نرم افزار Chromas تجزیه و تحلیل شدند. یافته ها: در اگزون های 20، 21 و 23 تغییری مشاهده نشد، اما در اگزون های 19 و 22 دو جهش R719W و R870H یافت شد که به ترتیب در دو و یک نفر از بیماران وجود داشتند. نتیجه گیری: از آنجا که تغییرات در اگزون های 19 و 22 باعث تغییر اسید آمینه ای در میوزین بتا می شود، جهش‌های ژن MYH7 در این اگزون ها، احتمالاً سهم به سزایی در بیماران HCM این استان دارند. به هر صورت، لازم است برای نتیجه گیری بهتر، بیماران بیشتری مورد مطالعه قرار گیرند

Mutation in second exon of myo15a gene cause of nonsyndromic hearing loss and its association in the Arab population in Iran

Hearing loss is a genetically and clinically heterogeneous defect and more than 140 loci and 65 genes have been identified to cause autosomal recessive non-syndromic hearing loss (ARNSHL). According to the previous studies, mutations in GJB2 are estimated to be involved in 18.17% of ARNSHL cases in the Iranian population; as a result, the remaining 81.83% of this disorder is yet ambiguous. This study aimed to determine the contribution of DFNB3 in hearing loss as well as the frequency of gene mutations in a population (Arab tribal origin) in the Southwest of Iran. In this descriptive laboratory study, we included 25 families from the Southwest of Iran and negative GJB2 gene. Linkage analysis was performed by DFNB3 (MYO15A) molecular markers (STR). The families with hearing loss linked to this locus were further analyzed for mutation detection. MYO15A gene exons were amplified and analyzed using direct DNA sequencing. In studied families, one family displayed linkage to DFNB3 locus. Identified mutations include substitution and substitute C for A in 1047 location of coding region of MYO15A gene (c.1047 C > A) in exon 2 which cause to change Tyrosin to stop codons (P.Y349X), results in the premature truncation at amino acid position 349

DFNB59 Gene Mutations and its Association with Deafness in Schoolchildren in Kohgilooyeh & Boyerahmad Province

Introduction & Objective: Hearing loss is a common disease affecting millions of people worldwide. Hearing loss can be caused due to genetic or environmental factors or even both. The genetic of hearing defect is highly heterogeneous and more than 100 genes are predicted to cause this disorder in humans. A newly identified gene (DFNB59) has been shown to cause deafness in some populations. Here we report mutation analysis for DFNB59 gene in 88 genetic non-syndromic hearing loss subjects. Materials & Methods: In this descriptive-lab based study which was conducted at the Cellular and Molecular Research Center of Shahrekord University of Medical Sciences, DNA was extracted from the peripheral blood samples using standard phenol chloroform procedure. Mutation analysis for DFNB59 gene was performed using PCR-SSCP/HA protocol. The suspected DFNB59 which was detected as shifted bands on PAGE were then confirmed by direct sequencing strategy. Results: Two DFNB59 polymorphisms including c.793C>G and c.793C>T were detected in 8 and 1 deaf subjects respectively. Conclusion: We conclude that there is no association between DFNB59 mutations and deafness in the studied patients in the region

Screening of three common mtDNA mutations among subjects with autosomal recessive non-syndromic hearing loss in Sistan va Baluchestan province, Iran

Background: Non-syndromic hearing loss may be induced by mutations in both nuclear and mitochondrial genes. Mutations in mtDNA are present in less than 1% of the children with pre-lingual deafness but are more prevalent later. Most of the molecular defects responsible for mitochondrial disorder, associated with hearing loss may be induced by mutations in the 12SrRNA and tRNA genes. This aim of this study was to investigate the frequency of three common mtDNA mutations including A1555G, A3243G and A7445G in a cohort of autosomal recessive non-syndromic hearing loss (ARNSHL) subjects in Sistan va Baluchestan province. Material and Methods: In this descriptive- experimental based study, a total of 110. ARNSHL subjects from Sistan va Baluchestan province were investigated for three common mtDNA mutations using PCR-RFLP procedure. The possible mutations were confirmed by direct sequencing. Results: None of the A1555G and A7445G mutations were detected in this study. However, we found one sample to carry A3243G mutation (0.9%). Moreover abolishing a MTTL1 restriction site close to A3243G mutation revealed a G3316A allelic variant in 0.9% of patients studied. Conclusion: This study showed that mtDNA mutations are responsible for less than 1% of pre-lingual ARNSHL associated subjects. The present study will improve the genetic counseling of hearing impaired patients in Sistan va Baluchestan province, Iran

Mutation in second exon of MYO15A gene cause of nonsyndromic hearing loss and its association in the Arab population in Iran

Hearing loss is a genetically and clinically heterogeneous defect and more than 140 loci and 65 genes have been identified to cause autosomal recessive non-syndromic hearing loss (ARNSHL). According to the previous studies, mutations in GJB2 are estimated to be involved in 18.17% of ARNSHL cases in the Iranian population; as a result, the remaining 81.83% of this disorder is yet ambiguous. This study aimed to determine the contribution of DFNB3 in hearing loss as well as the frequency of gene mutations in a population (Arab tribal origin) in the Southwest of Iran. In this descriptive laboratory study, we included 25 families from the Southwest of Iran and negative GJB2 gene. Linkage analysis was performed by DFNB3 (MYO15A) molecular markers (STR). The families with hearing loss linked to this locus were further analyzed for mutation detection. MYO15A gene exons were amplified and analyzed using direct DNA sequencing. In studied families, one family displayed linkage to DFNB3 locus. Identified mutations include substitution and substitute C for A in 1047 location of coding region of MYO15A gene (c.1047 C>A) in exon 2 which cause to change Tyrosin to stop codons (P.Y349X), results in the premature truncation at amino acid position 349