No abstract

This study shows that the mitochondrial A1555G mutation is among the significant causes of prelingual non-syndromic deafness in the Turkish population.

In this work we focus on a microsatellite-defined Y-chromosomal lineage (network 1n2) identified by us and reported in previous studies, whose geographic distribution and antiquity appear to be compatible with the Neolithic spread of farmers. Here, we set network 1.2 in the Y-chromosomal phylogenetic tree, date it with respect to other lineages associated with the same movements by other authors, examine its diversity by means of tri-and tetranucleotide loci and discuss the implications in reconstructing the spread of this group of chromosomes in the Mediterranean area. Our results define a tripartite phylogeny within HG 9 (Rosser et al. 2000), with the deepest branching defined by alleles T (Haplogroup Eu10) or G (Haplogroup Eu9) at M172 (Semino et al. 2000), and a subsequent branching within Eu9 defined by network 1n2. Population distributions of HG 9 and network 1n2 show that their occurrence in the surveyed area is not due to the spread of people from a single parental population but, rather, to a process punctuated by at least two phases. Our data identify the wide area of the Balkans, Aegean and Anatolia as the possible homeland harbouring the largest variation within network 1n2. The use of recently proposed tests based on the stepwise mutation model suggests that its spread was associated to a population expansion, with a high rate of male gene flow in the Turkish-Greek area.

We describe six Turkish patients with 5alpha-steroid reductase type 2 deficiency from unrelated Turkish families and a large pedigree of one of these patients who reside north-west of Anatolia. Patients NA, KS, BD and SY presented for evaluation of bilateral inguinal masses with female phenotypes. Patient ABE had penoscrotal hypospadias with male phenotype. Homozygous mutation of the 5alphaSR2 gene was identified in five of these patients by genomic DNA analysis. These mutations were Leu55Gln in exon 1 (in patients FG, BD and ABE), deltaMet157 in exon 3 (in patient NA), and splice junction abnormality in intron 1 (in patient SY). One individual (patient KS) was found to be a compound heterozygous carrier of two different mutations, Leu55Gln in exon 1 and Arg171Ser in exon 3. Patient FG had a large pedigree with the Leu55Gln mutation in exon 1. The pedigree of this family with marital consanguinity is remarkable, and possibly due to the isolation of this family because of economic and social problems. A further 85 individuals belonging to this family were analyzed for exon 1 Leu55Gln mutations in the 5alphaSR2 gene. Forty-two of these 85 individuals (49.41%) had this alteration; 11 were homozygous (8 genetic male, 3 genetic female) and 31 heterozygous (18 genetic male, genetic female) for this mutation. It was interesting to see asymptomatic homozygous female carriers. In conclusion, according to our results and those of other Turkish patients reported by different investigators, 5aSR2 gene mutation analysis, especially for Leu55Gln in exon 1 and deltaMet157 in exon 3, must be carried out in Turkish patients with male pseudohermaphroditism. Homozygous asymptomatic female carriers must be taken into consideration in this clinical entity, especially in a closed population, because of the risk of transmitting the disease to their offspring.

Rheumatic heart disease (RHD) or acute rheumatic fever (ARF) develops as a consequence of an exaggerated immune response to Group A beta haemolytic streptococci causing pharyngitis. The molecular mimicry appears between human cardiac myosin and M protein of group A streptococcal membranes. The polymorphism of the protein tyrosine phosphatase nonreceptor 22 (PTPN22) gene, which encodes an important negative regulator of T cell activation, has been reported to be associated with susceptibility to several autoimmune diseases such as SLE and RA. The objective of this study was to investigate whether PTPN22 R620W polymorphism confers susceptibility to RHD in Turkish population. PTPN 22 R620W (rs2476601, A/G) polymorphism was genotyped by PCR-RFLP in 121 patients with RHD who fulfilling the revised classification criteria of Jones, and 160 healthy control (HC), and also 137 SLE as a diseased-control. The frequency of GG and AG genotypes were found to be 94% (114), 6% (7) in RHD, respectively and 96% (153) and 4% (7) in HC, respectively. The homozygous AA genotype was not present in RHD and HC. There was no statistically significant difference between RHD and HC according to the frequency of AG heterozygote genotype (P = 0.831; OR = 1.13; 95% CI 0.37-3.46). The frequency of the rare allele A was also very similar in RHD patients and HC (3, 2% respectively). A similar result was also found between SLE and HC. Our results demonstrated that the PTPN22 R620W polymorphism is not associated with RHD nor with SLE in Turkish population.