Screening of 23 candidate genes by next-generation sequencing of patients with permanent congenital hypothyroidism: novel variants in TG, TSHR, DUOX2, FOXE1, and SLC26A7.

PURPOSE: To date, many genes have been associated with congenital hypothyroidism (CH). Our aim was to identify the mutational spectrum of 23 causative genes in Turkish patients with permanent CH, including thyroid dysgenesis (TD) and dyshormonogenesis (TDH) cases. METHODS: A total of 134 patients with permanent CH (130 primary, 4 central) were included. To identify the genetic etiology, we screened 23 candidate genes associated with CH by next-generation sequencing. For confirmation and to detect the status of the specific familial variant in relatives, Sanger sequencing was also performed. RESULTS: Possible pathogenic variants were found in 5.2% of patients with TD and in 64.0% of the patients with normal-sized thyroid or goiter. In all patients, variants were most frequently found in TSHR, followed by TPO and TG. The same homozygous TSHB variant (c.162 + 5G > A) was identified in four patients with central CH. In addition, we detected novel variants in the TSHR, TG, SLC26A7, FOXE1, and DUOX2. CONCLUSION: Genetic causes were determined in the majority of CH patients with TDH, however, despite advances in genetics, we were unable to identify the genetic etiology of most CH patients with TD, suggesting the effect of unknown genes or environmental factors. The previous studies and our findings suggest that TSHR and TPO mutations is the main genetic defect of CH in the Turkish population.

SCREENING OF PROP-1, LHX2 AND POU1F1 MUTATIONS IN PATIENTS WITH ECTOPIC POSTERIOR PITUITARY GLAND.

OBJECTIVE: Ectopic posterior pituitary gland (EPP) is usually characterized by an abnormal pituitary stalk and hypoplasia of the anterior hypophysis. The genetic mechanisms involved in the development of EPP remain uncertain. The aim of this study is to determine whether mutations in the three genes, PROP-1, LHX2, and POU1F1, are associated with the risk for and the characteristics of EPP. METHODS: In the Endocrinology Outpatient Clinic of "Dr. Behcet Uz" Children's Hospital, 27 patients with EPP were submitted to sequencing analyses of the PROP-1, LHX2, and POU1F1 genes. RESULTS: Growth hormone, thyrotropin, corticotropin, gonadotropin, and vasopressin deficiency were observed in 22 (81.5%), 23 (85.2%), 17 (63%), 14 (51.9%), and two (7.4%) patients. Thirteen patients (48.1%) presented with hyperprolactinemia. Fourteen patients (51%) had a history of birth dystocia, and 12 cases (42.1%) had a history of breech presentation. Central nervous system abnormalities included five cases with corpus callosum agenesis, one case with schizencephaly, and one case with Chiari type 1 malformation. We identified a homozygous p.S109* mutation in exon 2 in one male patient with EPP and two different PROP1 gene polymorphisms (A142T or c.109+3 G>A polymorphism) in thirteen patients. CONCLUSIONS: Our results suggest that PROP1 gene abnormalities might explain the genetic mechanisms involved in the development of EPP.

Sarcolemmal deficiency of sarcoglycan complex in an 18-month-old Turkish boy with a large deletion in the beta sarcoglycan gene.

Limb-girdle muscular dystrophy type 2E (LGMD-2E) is caused by autosomal recessive defects in the beta sarcoglycan (SGCB) gene located on chromosome 4q12. In this case report, the clinical findings, histopathological features and molecular genetic data in a boy with ß sarcoglycanopathy are presented. An 18-month-old boy had a very high serum creatinine phosphokinase (CPK) level that was accidentally determined. The results of molecular analyses for the dystrophin gene was found to be normal. He underwent a muscle biopsy which showed dystrophic features. Immunohistochemistry showed that there was a total loss of sarcolemmal sarcoglycan complex. DNA analysis revealed a large homozygous deletion in the SCGB gene. During 4 years of follow-up, there was no evidence to predict a severe clinical course except the muscle enzyme elevation and myopathic electromyography (EMG) finding. The presented milder phenotype of LGMD-2E with a large deletion in the SGCB gene provided additional support for the clinical heterogeneity and pathogenic complexity of the disease.

OROFACIAL FINDINGS AND DENTAL MANAGEMENT OF WILLIAMS SYNDROME.

Williams Syndrome is a microdeletion syndrome characterized by a number of developmental and physical abnormalities. The aim of the present study was to evaluate the oral abnormalities and dental management of patients with Williams Syndrome. Fifteen patients with Williams Syndrome aged between 3-20 years old were evaluated in this study. Oro-facial findings, dental plaque index and DMFT/dmft scores were recorded in each patient. Panoramic radiographs and extraoral, intraoral photographs were taken from all patients. According to the results of this study, the mean DMFT and dmft scores were 0.39 ± 0.12 and 1.81 ± 0.39, respectively. The most common oro-facial findings were detected as high palate (87%), diastema (60%), failure to thrive (60%), feeding difficulties (60%), vomiting (47%), macroglossi (47%), microdontia (40%) and frenulum hyperplasia (40%). All decayed teeth were restored with compomer and composite restorations. In conclusion, dentists play a significant role for improving the quality of life of the patients with Williams Syndrome to minimize or prevent dental abnormalities.

A cardio-facio-cutaneous syndrome case with tight Achilles tendons.

Cardio-facio-cutaneous syndrome (CFCS) is a multiple congenital anomaly disorder characterized by craniofacial features, cardiac defects, ectodermal anomalies and neurocognitive delay. Clinical findings of patients with CFCS show similarities to those of patients with Costello Syndrome (CS). CFCS and CS are caused by mutations in genes encoding proteins of the RAS-MAPK signaling pathway. Musculoskeletal findings including tight Achilles tendons and contractures of elbows, shoulders or hips have been reported in CS patients. However, limited extension of joints were observed in some patients with CFCS. According to the literature, no tight Achilles tendons have been reported in CFCS patients so far. In this case report, we present a male CFCS patient with tight Achilles tendons with a de-novo heterozygote N581D mutation in the BRAF gene detected by DNA sequence analysis.