👤 Filiz Hazan

Non-syndromic monogenic obesity is a rare cause of early-onset severe obesity in the childhood period. The aim of this study was to screen four obesity related genes ( Next-generation sequencing of all exons in Fifteen different variants in nineteen patients were identified with a variant detection rate of 12.3%. While six different heterozygous variants were observed in In conclusion, MC4R variants are the most common genetic cause of monogenic early-onset obesity, consistent with the literature. The c.496G>A variant in Show less

Trichorhinophalangeal syndrome type II (TRPSII) (synonym: Langer-Giedon syndrome) is a rare autosomal dominant contiguous gene syndrome, resulting from a microdeletion encompassing the EXT1 and the TRPS1 gene at 8q24 (MIM#150230). This syndrome combines the clinical features of two autosomal dominant disorders, trichorhinophalangeal syndrome type I (MIM#190350) and hereditary multiple osteochondromas type I (MIM # 133700). TRPSII is characterized by sparse scalp hair, a long nose with a bulbous tip, long flat philtrum, cone-shaped epiphyses of the phalanges, retarded bone age in infancy and multiple cartilaginous osteochondromas. We report a Turkish patient who had the clinical features and skeletal signs of TRPSII in whom a 13.8Mb deletion in 8q23.1- 8q24.13 was detected. Show less

Bardet-Biedl Syndrome (BBS) is a rare, autosomal-recessive ciliopathy characterized by obesity, rod-cone dystrophy, postaxial polydactyly, renal abnormalities, genital abnormalities and learning difficulties. To date, mutations in 21 different genes have been described as being responsible for BBS. Recently sequential gene sequencing has been replaced by next generation sequencing (NGS) applications. In this study, 15 patients with clinically diagnosed BBS were investigated using a next generation sequencing panel which included 17 known BBS causing genes (BBS1, BBS2, ARL6, BBS4, BBS5, MKKS, BBS7, TTC8, BBS9, BBS10, TRIM32, BBS12, MKS1, NPHP6, WDPCP, SDCCAG8, NPHP1). A genetic diagnosis was achieved in 13 patients (86.6%) and involved 9 novel and 3 previously described pathogenic variants in 6 of 17 BBS causing genes. BBS10 and BBS1 were the most commonly involved genes with frequencies of 31% and 23% respectively. Three of the 13 patients had an affected sibling. All affected siblings were found to be homozygous for the mutation detected in the proband. No evidence of triallelic inheritance was detected. Although limited association between certain genes and phenotypic features has been observed in this study, it is considered that additional studies are needed to better characterize the genotype-phenotype correlation of BBS. Our results demonstrate that NGS panels are feasible and effective method for providing high diagnostic yields in the diseases caused by multiple genes such as BBS. Show less

We report two newborns with female external genitalia and bilateral inguinal swelling who were diagnosed with 17β-hydroxysteroid dehydrogenase type 3 deficiency, a rare cause of 46,XY disorder of sexual development. The first case had normal clitoral size and vaginal and urethral openings, palpable gonads in the inguinal region, low testosterone, and low levels of basal and GNRH-stimulated gonadotropin. The second case had similar external genitalia, low testosterone but borderline basal and normal stimulated gonadotropin levels. Low testosterone/androstenedione ratios (0.22 and 0.24, respectively; normal, >0.8) after human chorionic gonadotropin stimulation indicated 17β-hydroxysteroid dehydrogenase type 3 deficiency. HSD17B3 sequencing revealed a homozygous novel mutation (c.464A>C, p.H155P) in exon 6 in the first case and homozygous c.239G>A (p.R80Q) in exon 3 in the second. Show less