Person: BEREKET, ABDULLAH
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BEREKET
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ABDULLAH
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Publication Open Access Homozygosity for a novel INHA mutation in two male siblings with hypospadias, primary hypogonadism, and high-normal testicular volume(2022-03-23) ŞAHİN, BAHADIR; DEMİRCİOĞLU, SERAP; BEREKET, ABDULLAH; GÜRAN, TÜLAY; Arslan Ateş E., Eltan M., Sahin B., Gurpinar Tosun B., Seven Menevse T., Geckinli B. B., Greenfield A., Turan S., Bereket A., Güran T.Background: The human INHA gene encodes the inhibin subunit alpha protein, which is common to both inhibin A and B. The functional importance of inhibins in male sex development, sexual function, and reproduction remain largely unknown. Objective: We report for the first time two male siblings with homozygous INHA mutations. Methods: The medical files were examined for clinical, biochemical, and imaging data. Genetic analysis was performed using next-generation and Sanger sequencing methods. Results: Two brothers complained of gynecomastia, testicular pain, and had a history of hypospadias. Biochemistry revealed low serum testosterone, high gonadotropin and anti-Mullerian hormone, and very low/undetectable inhibin concentrations, where available. Both patients had azoospermia in the spermiogram. We have identified a homozygous 2 bp deletion (c.208_209delAG, R70Gfs*3) variant, which leads to a truncated INHA protein in both patients, and confirmed heterozygosity in the parents. The external genital development, pubertal onset and progression, reproductive functions, serum gonadotropins, and sex hormones of mother and father, who were heterozygous carriers of the identified mutation, were normal. Conclusion: Homozygosity for INHA mutations causes decreased prenatal and postnatal testosterone production and infertility in males, while the heterozygous female and male carriers of INHA mutations do not have any abnormality in sex development and reproduction.Publication Open Access A novel deletion involving the first GNAS exon encoding Gsα causes PHP1A without methylation changes at exon A/B(2022-04-01) BEREKET, ABDULLAH; DEMİRCİOĞLU, SERAP; GÜRAN, TÜLAY; Campbell D., Reyes M., Kaygusuz S. B., Abalı S., Güran T., Bereket A., Kagami M., Turan S., Jüppner H.© 2022Individuals affected by pseudohypoparathyroidism type 1A (PHP1A) display hyperphosphatemia and hypocalcemia despite elevated PTH levels, as well as features of Albright Hereditary Osteodystrophy (AHO). PHP1A is caused by variants involving the maternal GNAS exons 1–13 encoding the stimulatory G protein α-subunit (Gsα). MLPA and aCGH analysis led in a male PHP1A patient to identification of a de novo 1284-bp deletion involving GNAS exon 1. This novel variant overlaps with a previously identified 1438-bp deletion in another PHP1A patient (ref. Li et al. (2020) [13], patient 2) that extends from the exon 1 promoter into the up-stream intronic region. This latter deletion is associated with reduced methylation at GNAS exon A/B, i.e. the differentially methylated region (DMR) that is demethylated in most pseudohypoparathyroidism type 1B (PHP1B) patients. In contrast, genomic DNA from our patient revealed no evidence for an epigenetic GNAS defect as determined by MS-MLPA and pyrosequencing. These findings thus reduce the region, which, in addition to other nucleotide sequences telomeric of exon A/B, may undergo histone modifications or interacts with transcription factors and possibly as-yet unknown proteins that are required for establishing the maternal methylation imprints at this site. Taken together, nucleotide deletions or changes within an approximately 1300-bp region telomeric of exon A/B could be a cause of PHP1B variants with complete or incomplete loss-of-methylation at the exon A/B DMR. In addition, when investigating patients with suspected PHP1A, MLPA should be considered to search for structural abnormalities within this difficult to analyze genomic region comprising GNAS exon 1.Publication Open Access Dysosteosclerosis: Clinical and radiological evolution reflecting genetic heterogeneity(2022-08-01) DEMİRCİOĞLU, SERAP; GÜRPINAR TOSUN, BUŞRA; GÜRAN, TÜLAY; BEREKET, ABDULLAH; ALAVANDA, CEREN; ARMAN, AHMET; DEMİRCİOĞLU S., Mumm S., ALAVANDA C., Kaygusuz B. S., GÜRPINAR TOSUN B., ARMAN A., Huskey M., GÜRAN T., Duan S., BEREKET A., et al.Dysosteosclerosis (DSS), the term coined in 1968 for ultrarare dysplasia of the skeleton featuring platyspondyly with focal appendicular osteosclerosis, has become generic by encompassing the genetic heterogeneity recently reported for this phenotype. We studied four unrelated Turkish patients with DSS to advance understanding of the new nosology. Patient 1 suffered femur fractures beginning at age 1 year. DSS was suspected from marked metaphyseal osteosclerosis in early childhood and subsequently platyspondyly accompanying patchy osteosclerosis of her appendicular skeleton. She harbored in SLC29A3, in 2012 the first gene associated with DSS, a unique homozygous duplication (c.303_320dup, p.102_107dupYFESYL). Patient 2 presented similarly with fractures and metaphyseal osteosclerosis but with no platyspondyly at age 2 months. She was homozygous for a novel nonsense mutation in SLC29A3 (c.1284C>G, p.Tyr428*). Patient 3 had ocular disease at age 2 years, presented for short stature at age 11 years, and did not begin to fracture until age 16 years. Radiographs showed mild platyspondyly and focal metaphyseal and femoral osteosclerosis. She was homozygous for a unique splice site mutation in TNFRSF11A (c.616+3A>G). Patient 4 at age 2 years manifested developmental delay and frequent infections but did not fracture. He had unique metadiaphyseal splaying and osteosclerosis, vertebral end-plate osteosclerosis, and cortical thinning of long bones but no mutation was detected of SLC29A3, TNFRSF11A, TCIRG1, LRRK1, or CSF1R associated with DSS. We find that DSS from defective SLC29A3 presents earliest and with fractures. DSS from compromised TNFRSF11A can lead to optic atrophy as an early finding. Negative mutation analysis in patient 4 suggests further genetic heterogeneity underlying the skeletal phenotype of DSS. (c) 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.Publication Open Access Misalignment among adolescents living with obesity, caregivers, and healthcare professionals: ACTION Teens global survey study(2022-11-01) BEREKET, ABDULLAH; Halford J. C. G., BEREKET A., Bin-Abbas B., Chen W., Fernandez-Aranda F., Garibay Nieto N., Lopez Siguero J. P., Maffeis C., Mooney V., Osorto C. K., et al.Background There is limited evidence regarding the experiences, challenges, and needs of adolescents living with obesity (ALwO), their caregivers, and healthcare professionals (HCPs). Objectives The cross-sectional, survey-based global ACTION Teens study aimed to identify perceptions, attitudes, behaviours, and barriers to effective obesity care among ALwO, caregivers of ALwO, and HCPs. Methods ALwO (aged 12 to N = 5275), caregivers (N = 5389), and HCPs treating ALwO (N = 2323) from 10 countries completed an online survey (August-December 2021). Results Most ALwO perceived their weight as above normal (76% vs. 66% of caregivers), were worried about its impact on their health (85% vs. 80% of caregivers), and recently made a weight loss attempt (58%). While 45% of caregivers believed ALwO would slim down with age, only 24% of HCPs agreed. Most commonly reported weight loss motivators for ALwO were wanting to be more fit/in better shape according to ALwO (40%) and caregivers (32%), and improved confidence/social life according to HCPs (69%). ALwO weight loss barriers included lack of hunger control (most commonly reported by ALwO/caregivers), lack of motivation, unhealthy eating habits (most commonly agreed by HCPs), and lack of exercise. Conclusions Misalignment between ALwO, caregivers, and HCPs-including caregivers\" underestimation of the impact of obesity on ALwO and HCPs\" misperception of key motivators/barriers for weight loss-suggests a need for improved communication and education.