Context Primary ovarian insufficiency (POI) encompasses a spectrum of premature menopause, including both primary and secondary amenorrhea. For 75% to 90% of individuals with hypergonadotropic hypogonadism presenting as POI, the molecular etiology is unknown. Common etiologies include chromosomal abnormalities, environmental factors, and congenital disorders affecting ovarian development and function, as well as syndromic and nonsyndromic single gene disorders suggesting POI represents a complex trait. Objective To characterize the contribution of known disease genes to POI and identify molecular etiologies and biological underpinnings of POI. Design, Setting, and Participants We applied exome sequencing (ES) and family-based genomics to 42 affected female individuals from 36 unrelated Turkish families, including 31 with reported parental consanguinity. Results This analysis identified likely damaging, potentially contributing variants and molecular diagnoses in 16 families (44%), including 11 families with likely damaging variants in known genes and five families with predicted deleterious variants in disease genes (IGSF10, MND1, MRPS22, and SOHLH1) not previously associated with POI. Of the 16 families, 2 (13%) had evidence for potentially pathogenic variants at more than one locus. Absence of heterozygosity consistent with identity-by-descent mediated recessive disease burden contributes to molecular diagnosis in 15 of 16 (94%) families. GeneMatcher allowed identification of additional families from diverse genetic backgrounds. Conclusions ES analysis of a POI cohort further characterized locus heterogeneity, reaffirmed the association of genes integral to meiotic recombination, demonstrated the likely contribution of genes involved in hypothalamic development, and documented multilocus pathogenic variation suggesting the potential for oligogenic inheritance contributing to the development of POI.

Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan.

Context: Congenital hypothyroidism, the most frequent endocrine congenital disease, can occur either based on a thyroid hormone biosynthesis defect or can predominantly be due to thyroid dysgenesis. However, a genetic cause could so far only be identified in less than 10% of patients with a thyroid dysgenesis. Objectives: Exome sequencing was used for the first time to find additional genetic defects in thyroid dysgenesis. Patients and Methods: In a consanguineous family with thyroid dysgenesis, exome sequencing was applied, and findings were further validated by Sanger sequencing in a cohort of 94 patients with thyroid dysgenesis. Results: By exome sequencing we identified a homozygous missense mutation (p.Leu597Ser) in the SLC26A4 gene of a patient with hypoplastic thyroid tissue, who was otherwise healthy. In the cohort of patients with thyroid dysgenesis, we observed a second case with a homozygous missense mutation (p.Gln413Arg) in the SLC26A4 gene, who was additionally affected by severe hearing problems. Both mutations were previously described as loss-of-function mutations in patients with Pendred syndrome and nonsyndromic enlarged vestibular aqueduct. Conclusion: We unexpectedly identified SLC26A4 mutations that were hitherto diagnosed in thyroid dyshormonogenesis patients, now for the first time in patients with structural thyroid defects. This result resembles the historic description of thyroid atrophy in patients with the so-called myxedematous form of cretinism after severe iodine deficiency. Most likely the thyroid defect of the two homozygous SLC26A4 gene mutation carriers represents a kind of secondary thyroid atrophy, rather than a primary defect of thyroid development in the sense of thyroid agenesis. Our study extends the variable clinical spectrum of patients with SLC26A4 mutations and points out the necessity to analyze the SLC26A4 gene in patients with apparent thyroid dysgenesis in addition to the known candidate genes TSHR, PAX8, NKX2.1, NKX2.5, and FOXE1.

Epidemiologic and clinical features of type 1 diabetes mellitus (T1DM) may show substantial differences among countries. The primary goal in the management of T1DM is to prevent micro- and macrovascular complications by achieving good glycemic control. The present study aimed to assess metabolic control, presence of concomitant autoimmune diseases, and of acute and long-term complications in patients diagnosed with T1DM during childhood and adolescence. The study also aimed to be a first step in the development of a national registry system for T1DM, in Turkey. Based on hospital records, this cross-sectional, multicenter study included 1 032 patients with T1DM from 12 different centers in Turkey, in whom the diagnosis was established during childhood. Epidemiological and clinical characteristics of the patients were recorded. Metabolic control, diabetes care, complications, and concomitant autoimmune diseases were evaluated. Mean age, diabetes duration, and hemoglobin A1c level were 12.5 ± 4.1 years, 4.7 ± 3.2 years, and 8.5 ± 1.6%, respectively. Acute complications noted in the past year included ketoacidosis in 5.2% of the patients and severe hypoglycemia in 4.9%. Chronic lymphocytic thyroiditis was noted in 12%, Graves' disease in 0.1%, and celiac disease in 4.3% of the patients. Chronic complications including neuropathy, retinopathy, and persistent microalbuminuria were present in 2.6%, 1.4%, and 5.4% of the patients, respectively. Diabetic nephropathy was not present in any of the patients. Mean diabetes duration and age of patients with neuropathy, retinopathy and microalbuminuria were significantly different from the patients without these long-term complications (p<0.01). A significant difference was found between pubertal and prepubertal children in terms of persistent microalbuminuria and neuropathy (p=0.02 and p<0.001, respectively). Of the patients, 4.4% (n:38) were obese and 5% had short stature; 17.4% of the patients had dyslipidemia, and 14% of the dyslipidemic patients were obese. Although the majority of the patients in the present study were using insulin analogues, poor glycemic control was common, and chronic complications were encountered.

Congenital portosystemic shunt (CPSS) is persistence of an anomalous embryological connection of the portal vein with a large vein of the vena cava system. Clinical presentations include neonatal cholestasis, liver tumors, and encephalopathy, but can be variable in timing and symptomatology. We report 2 girls who presented 10 years apart with the same complaint of early pubarche at age 7 years, with inappropriately low DHEAS levels. In addition to hyperandrogenemia (elevated testosterone and androstenedione) and advanced bone age, both had hyperinsulinemia, and hypothyroxinemia. The 2nd case also had symptomatic hypoglycemia. Presentation of CPSS with this combination of findings in prepubertal children has not been reported previously. With further investigations, we proposed novel mechanisms explaining these manifestations. Hyperandrogenemia is caused by decreased hepatic sulfation of DHEA to less active DHEAS due to shunting of DHEA to systemic circulation. Elevated DHEA is then used for synthesis of more potent androgens. Shunting of postabsorbtive glucose from portal to systemic circulation causes early hyperglycemia leading to exaggerated insulin secretion. Insulin bypasses the hepatic metabolism directly entering into the systemic circulation, which results in hyperinsulinemia, then in turn causes late hypoglycemia. Finally, hypothyroxinemia was linked to thyroxin-binding globulin deficiency, which has not been reported in CPSS.