Novel growth hormone-releasing hormone receptor gene mutations in Turkish children with isolated growth hormone deficiency.

OBJECTIVE: Isolated growth hormone deficiency (IGHD) is defined as a medical condition associated with growth failure due to insufficient production of GH or lack of GH action. Mutations in the gene encoding for GH-releasing hormone receptor (GHRHR) have been detected in patients with IGHD type IB. However, genetic defects on GHRHR causing IGHD in the Turkish population have not yet been reported. To identify mutations on GHRHR gene in a population of Turkish children with IGHD. METHODS: Ninety-six Turkish children with IGHD were included in this study. Exon1-13 and exon/intron boundaries of GHRHR were amplified by suitable primers. The polymerase chain reaction products for GHRHR gene were sequenced with primers. RESULTS: We analyzed the GHRHR gene for mutations in ninety-six patients with IGHD based on sequence results. We identified novel p.K264E, p.S317T, p.S330L, p.G369V, p.T257A and C base insertion on position 380 (c.380inserC) mutations. In 5 of the patients, the mutation was homozygote and in 1-heterozygote (p.S317T). CONCLUSION: Six new missense mutations and one first case of insertion mutations for the GHRHR gene are reported.

Multiple sclerosis: association with the interleukin-1 gene family polymorphisms in the Turkish population.

BACKGROUND: Multiple Sclerosis (MS) is a neurodegenerative disease. It involves inflammation and demyelination. Since cytokines play an important role in the development of MS, genes encoding cytokines such as the Interleukin (IL)-1 family are candidate genes for MS susceptibility. OBJECTIVE: To determine the relationship between IL-1 gene family and MS in the Turkish population. METHODS: A total of 409 MS patients and 256 healthy controls were included in the study. IL-1A -889 (rs1800587), IL-1 RN variable number tandom repeat (VNTR), IL-1B -511 (rs 16944) and IL-1B +3953 (rs 1143634) polymorphisms were investigated from the genomic DNA, obtained via blood samples. RESULTS: No association was found between IL-1A and IL-1RN polymorphisms and susceptibility to MS. However, we have found significantly decreased frequency of IL-1B -511 genotype (p = 0.004) in MS patients compared to controls. In addition, there was a significant association between IL-1B -511 (1/2) genotype and early onset MS (EOMS) (p = 0.0001). CONCLUSIONS: Individuals with the 2/2 genotype of IL-1B -511 have significantly decreased incidence of MS, suggesting a protective role for this genotype in the Turkish population. Additionally, IL-1B -511 (1/2) genotype was determined as a possible risk factor for EOMS.