ACTA ENDOCRINOLOGICA (BUC)

Introduction. KCNJ11 gene activating mutations play a major role in the development of neonatal diabetes mellitus (NDM). KCNJ 11 gene encodes the Kir 6.2 subunit of ATP- sensitive potassium channel which is a critical regulator of pancreatic beta-cell insulin secretion. Aim. To study KCNJ11 gene mutations in infants with NDM and the effect of sulfonylurea treatment on the glycemic control in patients with KCNJ11 gene mutation. Subjects and methods. Thirty infants with NDM were screened for KCNJ11 gene mutations by DNA sequencing, insulin therapy was replaced by sulfonylurea treatment in patients with mutations. Results. R201C heterozygous mutation was found in one patient who was successfully shifted from insulin therapy to sulfonylurea treatment, while E23k, I337V, and S385C polymorphisms were detected in 14 patients. Conclusion. Screening for KCNJ 11 gene mutations could lead to identification of patients with mutations who can be successfully shifted from insulin therapy to sulfonylurea treatment improving their quality of life.

Context. Mutations in the androgen receptor (AR) gene result in androgen insensitivity syndrome (AIS). In milder forms of AIS, male infertility appears as primary or even sole symptom. Identification of such mutations is fundamental for accurate diagnosis and for appropriate genetic counseling.\r\nObjectives. To determine the prevalence of known point mutations in the AR gene causing male infertility in Syrian\r\nazoospermic men.\r\nDesign. 15 known point mutations in the AR gene were screened in a cohort of 110 Syrian infertile men.\r\nSubjects and methods. The study involved 173 Syrian infertile men suffering from non-obstructive azoospermia.\r\nChromosome aberrations and Y microdeletions were excluded in 110 patients, which were further tested for point mutations in the AR gene by real time PCR or DNA sequencing.\r\nResults. The prevalence of AR mutations in our cohort was 3.6% (4/110). We found two patients with the Ala474Val\r\nmutation and one patient bearing the Pro390Ser mutation. Furthermore, one patient had a new mutation, del 57Leu,\r\ndescribed for the first time in an infertile man. None of the 50 fertile Syrian men had this mutation, indicating that it is not a sequence polymorphism in the Syrian population.\r\nConclusion. The del 57Leu mutation in the AR gene is a possible cause of idiopathic male infertility. Furthermore, the Ala474Val and Pro390Ser mutations (previously found in several infertile men in Italy) might be significant markers for male infertility in Mediterranean populations.