Melanocortin-4 Receptor Gene Mutations in a Group of Turkish Obese Children and Adolescents.

OBJECTIVE: Melanocortin-4 receptor (MC4R) mutations are the most common known cause of monogenic obesity. Data regarding MC4R mutations in Turkish subjects are limited. To determine the prevalence of MC4R mutations in a group of Turkish morbid obese children and adolescents. METHODS: MC4R was sequenced in 47 consecutive morbidly obese children and adolescents (28 girls and 19 boys, aged 1-18 years) who presented during a one-year period. Inclusion criterion was a body mass index (BMI) ≥120% of the 95th percentile or ≥35 kg/m2. Patients with chronic diseases, Cushing syndrome, hypothyroidism, or suspected syndromes that could cause obesity were excluded. Onset of obesity was before age 10 years in all subjects. RESULTS: Mean age was 13.2±4.1 years, age at onset of obesity 5.1±2.1 years, height standard deviation (SD) score 1.21±0.93, BMI 40.0±8.8 kg/m2, and BMI SD score was 2.72±0.37. One novel (c.870delG) and two previously reported (c.496 G>A, c.346_347delAG) mutations were found in four (8.5%) obese children and adolescents. The novel mutation (c.870delG) was predicted to be a disease-causing frame-shift mutation using in silico analyses. Fasting glucose and lipid levels of the patients with MC4R mutation were normal, but insulin resistance was present in two of the subjects. Six more individuals with MC4R mutation (1 child, 5 adults) were detected following analyses of the family members of affected children. CONCLUSION: MC4R mutations are frequently found in morbid obese Turkish children and adolescents.

Prognostic impact of RUNX1 and ETV6 gene copy number on pediatric B-cell precursor acute lymphoblastic leukemia with or without hyperdiploidy.

The ETV6/RUNX1 fusion gene is a valuable prognostic marker that is frequently observed in B-cell precursor acute lymphoblastic leukemia (B-cell ALL). However, the clinical significance of copy number aberrations in these genes remains unclear. In this study, the effects of various aberrations inETV6 and RUNX1 gene copy number on disease prognosis were evaluated in 21 pediatric patients diagnosed with B-cell ALL with/without t(12;21). The prognostic significance of changes in gene copy number of ETV6 or RUNX1 in the presence or absence of hyperdiploidy, trisomy 21, and t(12;21) translocation were also evaluated. RUNX1 gene copy number amplifications were detected in 83 % of the patients who lacked t(12;21) and in all of the patients with hyperdiploidy. Trisomy 21 was detected in 78 % of the patients with hyperdiploidy. Changes in ETV6 gene copy number were detected in patients who lacked both the t(12;21) translocation and RUNX1 gene copy number amplifications. However, RUNX1 gene copy number amplification and ETV6 deletion were observed in all of the patients with t(12;21). RUNX1 gene copy number amplification was associated with hyperdiploidy, but not with t(12;21). Thus, the evaluation of distinct FISH and cytogenetic patterns in patients with B-cell ALL may strengthen the prognostic significance of changes in gene copy number.

Investigation of androgen receptor gene mutations in a series of 21 patients with 46,XY disorders of sex development.

AIM: Androgen receptor (AR) gene mutations are the leading cause of 46,XY disorders of sex development (DSD) and are associated with varying degrees of androgen insensitivity. The aim of this study is to investigate AR gene mutations in 46,XY DSD patients with normal testosterone secretion, either normal or high testosterone/dihydrotestosterone (T/DHT) ratio and normal SRD5A2 gene analysis, collectively, suggestive of androgen insensitivity syndrome (AIS). METHODS: We direct sequenced all eight exons of the AR gene in 21 index patients with varying degrees of undervirilization. RESULTS: We detected AR gene alterations in five patients. In patients with complete AIS we found p.Val30Met in exon 1 and p.Gly689* in exon 4. One patient with partial AIS had p.Gln712Glu in exon 4. In two patients with partial phenotype, we found common p.Glu213Glu (c.639G>A) SNP, and an additional p.Ile817Ile (c.2451T>C) mutation was found in one of these two patients. DISCUSSION: Despite the fact that T/DHT ratio is frequently used in diagnosis of AIS, lack of precisely determined cutoffs compromises correct diagnosis. Hence, depending on clinical and biochemical findings solely may delay correct diagnosis. Direct sequence analysis of the AR is essential for precise diagnosis of AIS.