No abstract

Growing evidence suggests that metabolic syndrome (MetS) has both genetic and environmental bases. We estimated the heritability of the MetS and its components in the families from the Tehran Lipid and Glucose Study (TLGS). We investigated 904 nuclear families in TLGS with two biological parents and at least one offspring (1565 parents and 2448 children), aged 3-90 years, for whom MetS information was available and had at least two members of family with MetS. Variance component methods were used to estimate age and sex adjusted heritability of metabolic syndrome score (MSS) and MetS components using SOLAR software. The heritability of waist circumference (WC), HDL-cholesterol (HDL-C), triglycerides (TGs), fasting blood sugar (FBS), systolic blood pressure (SBP) and diastolic blood pressure (DBP) as continuous traits after adjusting for age and gender were 27, 46, 36, 29, 25, 26 and 15%, respectively, and MSS had a heritability of 15%. When MetS components were analysed as discrete traits, the estimates of age and gender adjusted heritability for MetS, abdominal obesity, low HDL-C, high TG, high FBS and high blood pressure (BP) were 22, 40, 34, 38 and 23%, respectively (P < 0·05). Three factors were extracted from the six continuous traits of the MetS including factor I (BP), factor II (lipids) and factor III (obesity and FBS). Heritability estimation for these three factors were 7, 13 (P < 0·05) and 2%, respectively. The highest heritability was for HDL-C and TG. The results strongly encourage efforts to identify the underlying susceptibility genes.

Thyroid carcinoma (TC) is the most frequent malignant neoplasm of the endocrine system. Molecular methods for diagnosis of invasive thyroid disease can be effectively adopted. Epigenetic factors play an important role in the diversity patterns of gene expression and the phenotypic and biological characteristics of TC subtypes. We aimed to review epigenetic changes in the main subtypes of TC, along with a presentation of the methods that have examined these changes, and active clinical trials for the treatment of advanced TCs targeting epigenetic changes. A literature analysis was performed in MEDLINE using PubMed, Elsevier, and Google Scholar for studies published up to 2016, using the keywords: "Epigenetic alterations" OR "Epigenetic changes", "thyroid cancers", "papillary thyroid cancer", "medullary thyroid cancer", "follicular thyroid cancer", and "anaplastic thyroid cancer", which resulted in 310 articles in English. All related abstracts were reviewed and studies were included that were published in English, had available full text, and determined the details of the methods and materials associated with the epigenetic patterns of TC and its subtypes (100 articles). Analysis of epigenetic alterations in TC subtypes helps to identify pathogenesis and can play an important role in the classification and diagnosis of tumors. Epigenetic mechanisms, especially aberrant methylation of DNA and microRNAs (miRs), are likely to play an important role in thyroid tumorigenesis. Further studies are required to elucidate the role of histone modification mechanisms in TC development.