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    CAG polymorphism in the androgen receptor gene in women may be associated with nodulocystic acne
    (Termedia Publishing House Ltd, 2019) Demirkan, Serkan; Sayin, Derya Beyza; Gunduz, Ozgur
    Introduction: Acne vulgaris (AV) is a multifactorial, inflammatory disease of the pilosebaceous unit. Hormones play a major role in the pathogenesis of acne. In cases of hyperandrogenism; hirsutism, acne, seborrhoea and alopecia appear in women. However, severe acne can also be seen without evidence of hyperandrogenism. In this case, hypersensitivity of the androgen receptor gene (ARG) encoded in the X chromosome, which is the only receptor for androgens, can be considered. ARG contains a polymorphic CAG triple loop encoding the polyglutamine pathway at the 5'end of exon 1. Aim: To investigate CAG repeat polymorphism in the ARG in nodulocystic acne patients in Turkish population. Material and methods: This prospective clinical study was conducted between 2016 and 2017 in accordance with the tenets of the Declaration of Helsinki. DNA isolation from blood was performed using the RTA (R) Genomic DNA Isolation Kit. The fragment lengths obtained from the device to determine CAG repeat numbers were analysed based on -288 bp length 22 CAG repeat content. Results: A total of 199 subjects; 100 patients (51 males, 49 females) and 99 controls (49 males, 50 females) were included in the study. The mean allele length in the patient group was 19.34; and 19.7 in the control group. There was a statistically significant difference between female patients and the control group, when the patients and control groups were compared by gender (p = 0.0059). Conclusions: The CAG trinucleotide repeat count in the ARG may be associated with acne, without hirsutism findings.
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    Methylation and cancer: Review
    (Ortadogu Ad Pres & Publ Co, 2008) Sayin, Derya Beyza
    DNA methylation is the major epigenetic modification in mammals, and is seen in CpG dinucleotides. In normal cells, the CpG dinucleotides in repetitive DNA are methylated, and CpG islands, which are found in the promotor region in 50% of genes, are demethylated. Epigenetic modifications may be defined as inheritable gene expression changes, without altering the primary sequence of DNA. It is well established that epigenetic modifications are as important as genetic changes in cancer development. Cancer cells show genomic hypomethylation and gene promotor hypermethylation. Both are independent from each other, but are effective in cancerogenesis in different ways. Hypermethylation of the promotor has a supressive effect on the downstream gene, and is important in turnout supressor gene inactivation. hMLH1 and O-6-MGMT gene methylations are the most studied among different cancer types. Knudson's two hit hypothesis is the most common hypotesis for cancer development, and one of these hits may be epigenetic. Genomewide hypomethylation may favor for genomic instability and reactivation of parasitic sequences. Promotor hypermethylation may show different patterns in different cancers, or different types of the same cancer, and methylation patterns may be useful as a cancer biomarker or a prognostic marker. Epigenetic mutations are reversible, and there is sparse promotor hypermethylation in normal cells, which makes demethylating agents highly specific for cancer cells. Increasing our knowledge on the methylation changes in cancer cells will improve our approaches to the treatment, diagnosis and prevention of cancer.
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    The spectrum of FMF mutations and genotypes in the referrals to molecular genetic laboratory at KÄaut +/- rÄaut +/- kkale University in Turkey
    (Springer, 2009) Günel-Özcan, Ayşen; Sayin, Derya Beyza; Mısırlıoğlu, Emine Dibek; Guliter, Sefa; Yakaryilmaz, Fahri; Ensari, Cüneyt
    Familial Mediterranean Fever (FMF) is an autosomal recessive genetic disorder characterised by recurrent and self-limited abdominal pain, synovitis and pleuritis. MEFV gene mutations are responsible from the disease and its protein product, pyrin or marenostrin, plays an essential role in the regulation of the inflammatory reactions. MEFV gene contains 10 exons and most of the mutations have been found on the last exon. Up to date, 152 mutations and polymorpisms have been reported inwhere V726A, M694V, M694I, M680I and E148Q are the most common mutations. In this study, MEFV allele frequencies of 136 individuals (60 from Pediatry, 76 from Internal Medicine) have been evaluated, and compared with each other. Asymptomatic individuals with FMF family history (4 from Pediatry, 6 from Internal Medicine) were excluded from the analysis. The prominent mutations indicated in the Pediatry group are V726A, M694V and M680I (G/C) and with the allele frequency of 0.06, 0.05 and 0.04 respectively while they were E148Q, M694V, M680I (G/C) in the Internal Medicine group with the allele frequency of 0.12, 0.08 and 0.04. The E148Q mutation is significantly overrepresented in the adult referrals (P = 0.02). Mutation on both alleles was observed in only 12% of cases. Overall mutation frequency was low, seen in 26.2% (66/252). However, when only diagnosed patients were analyzed it is 72.7% (16/22). It is also interesting that 63% of individuals are female that there may be sex influence on FMF phenotype.