ABSTRACT. Infertility affects about 10-15% of all couples attempting pregnancy with infertility attributed to the male partner in approximately half of the cases. Proposed causes of male infertility include sperm motility disturbances, Y chromosome microdeletions, chromosomal abnormalities, single gene mutations, and sperm mitochondrial DNA (mtDNA) rearrangements. To investigate the etiology of decreased sperm fertility and motility of sperm and to develop an appropriate therapeutic strategy, the molecular basis of these defects must be elucidated. In this study, we aimed to reveal the relationships between the genetic factors including sperm mtDNA mutations, Y chromosome microdeletions, and sperm parameters that can be regarded as candidate factors for male infertility. Thirty men with a history of infertility and 30 fertile men were recruited to the study. Y chromosome microdeletions were analyzed by multiplex PCR. Mitochondrial genes ATPase6, Cytb, and ND1, were amplified by PCR and then analyzed by direct sequencing. No Y chromosome microdeletions were detected in either group. However, a total of 38 different nucleotide substitutions were identified in the examined mitochondrial genes in both groups, all of which are statistically non-significant. Fifteen substitutions caused an amino acid change and 12 were considered novel mutations. As a conclusion, mtDNA mutations and Y chromosome microdeletions in male infertility should be examined in larger numbers in order to clarify the effect of genetic factors.

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Objectives To detect autosomal genetic defects and to determine candidate genes in Sertoli cell‐only syndrome infertile men. Methods Single‐nucleotide polymorphism + comparative genomic hybridization microarray technology was carried out on 39 Sertoli cell‐only syndrome infertile patients in the present study. Array comparative genomic hybridization compares the patient's genome against a reference genome, and identifies uncover deletions, amplifications and loss of heterozygosity. Results A link between defective spermatogenesis genes and infertility was examined, and amplifications and deletions in several genes were detected, including homeobox gene; synaptonemal complex element protein 1; collagen, type I, alpha 1; imprinted maternally expressed transcript; and potassium voltage‐gated channel subfamily Q member 1. Conclusions The present data suggest that several genes can play an important role in spermatogenesis and progression of Sertoli cell‐only syndrome.

Congenital adrenal hyperplasia (CAH) is a group of genetic endocrine disorders, caused by enzyme deficiencies in the conversion of cholesterol to cortisol. More than 90% of the cases have 21-hydroxylase deficiency (21-OHD). The clinical phenotype of the disease is classified as classic, the severe form, and nonclassic, the mild form. In this study, it was planned to characterize the mutations that cause 21-OHD in Turkish CAH patients by direct sequencing and multiplex ligation-dependent probe amplification (MLPA) analysis and to investigate the type of CAH (classic or nonclassic type) that these mutations cause. A total of 124 CAH patients with 21-OHD and 100 healthy volunteers were recruited to the study. Most of the mutations were detected by direct sequencing. Large gene deletions/duplications/conversions were investigated with MLPA analysis. Results were evaluated statistically. At the end of our study, 66 different variations were detected including SNPs and deletions/duplications/conversions. Of these variations, 18 are novel, of which three cause amino acid substitutions. In addition, 15 SNPs which cause amino acid changes were identified among these variations. If similar results are obtained in different populations, these mutations, in particular the novel mutation 711 G>A, may be used as markers for prenatal diagnosis.

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