Gordon Holmes syndrome (GHS) is characterized by cerebellar ataxia/atrophy and normosmic hypogonadotropic hypogonadism (nHH). The underlying pathophysiology of this combined neurodegeneration and nHH remains unknown. We aimed to provide insight into the disease mechanism in GHS. We studied a cohort of 6 multiplex families with GHS through autozygosity mapping and whole-exome sequencing. We identified 6 patients from 3 independent families carrying loss-of-function mutations in PNPLA6, which encodes neuropathy target esterase (NTE), a lysophospholipase that maintains intracellular phospholipid homeostasis by converting lysophosphatidylcholine to glycerophosphocholine. Wild-type PNPLA6, but not PNPLA6 bearing these mutations, rescued a well-established Drosophila neurodegenerative phenotype caused by the absence of sws, the fly ortholog of mammalian PNPLA6. Inhibition of NTE activity in the LβT2 gonadotrope cell line diminished LH response to GnRH by reducing GnRH-stimulated LH exocytosis, without affecting GnRH receptor signaling or LHβ synthesis. These results suggest that NTE-dependent alteration of phospholipid homeostasis in GHS causes both neurodegeneration and impaired LH release from pituitary gonadotropes, leading to nHH.

Defects in genes mediating thyroid hormone biosynthesis result in dyshormonogenic congenital hypothyroidism (CH). Here, we report homozygous truncating mutations in SLC26A7 in 6 unrelated families with goitrous CH and show that goitrous hypothyroidism also occurs in Slc26a7 -null mice. In both species, the gene is expressed predominantly in the thyroid gland, and loss of function is associated with impaired availability of iodine for thyroid hormone synthesis, partially corrected in mice by iodine supplementation. SLC26A7 is a member of the same transporter family as SLC26A4 (pendrin), an anion exchanger with affinity for iodide and chloride (among others), whose gene mutations cause congenital deafness and dyshormonogenic goiter. However, in contrast to pendrin, SLC26A7 does not mediate cellular iodide efflux and hearing in affected individuals is normal. We delineate a hitherto unrecognized role for SLC26A7 in thyroid hormone biosynthesis, for which the mechanism remains unclear.

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.

Hyperprolactinemia may be due to various etiological factors and may present with different signs and symptoms. It is relatively less frequent in childhood than in adulthood. The aim of this study was to evaluate retrospectively the clinical course and outcome of hyperprolactinemia in pediatric patients. We investigated the records of 21 patients with hyperprolactinemia who attended a tertiary hospital. Menstrual problems, galactorrhea , and headache were the most common presenting symptoms. Hyperprolactinemia was due to microadenoma in 10, macroadenoma in 7, and was drug-induced in 4 patients. Bromocriptine and cabergoline were equally effective in lowering serum prolactin levels. Surgical treatment in children with macroprolactinoma was not curative and dopamine agonist therapy was required postoperatively. In the presence of any clinical symptom or sign suggestive of suppression of the pituitary-gonadal axis, hyperprolactinemia should not be forgotten as a probable diagnosis. Medical therapy seems effective in microadenoma. Surgical therapy may not be successful in macroadenoma and recurrence is frequent.

Early diagnosis and treatment of testicular adrenal rest tumors (TART) is important for gonadal functions and fertility protection in boys with congenital adrenal hyperplasia (CAH). In this descriptive study, we investigated the prevalence of TART in boys with 21-hydroxylase deficient (21OHD) CAH followed in our pediatric endocrine clinic. The study group consisted of 14 male patients with a mean age of 9.6 ± 5.1 (range: 0.8-18.3) years. Six (42.9%) of the 14 patients were diagnosed as having salt-wasting type (SW) and eight (57.1%) patients - as having the simple virilizing (SV) form of 21OHD. Mean age at diagnosis was 2.9 ± 2.7 (range: 0.03-6.3) years. Two different radiologists performed scrotal ultrasonography. Chronological age, bone age, and anthropometric measurements were evaluated. Serum adrenocorticotropic hormone (ACTH), 17-alpha-hydroxyprogesterone (17OHP) and androstenedione levels were also evaluated in all patients during the follow-up period. Scrotal ultrasonography revealed bilateral TART in two patients (14.3%) and testicular microlithiasis (TM) in four patients (28.6%). One patient had both TART and TM bilaterally. During the follow-up period, the mean serum adrenocorticotropic hormone, 17OHP and androstenedione levels in the total group of patients were 130.0 ± 179.1 pg/mL (21.7-726.5), 5.8 ± 3.3 ng/mL (0.8-11.4) and 4.3 ± 4.1 (0.2-11.0) ng/mL, respectively. Microlithiasis or TART may be frequently encountered during the follow-up of patients with CAH. In order to prevent late complications including infertility, we suggest that ultrasonographic evaluations be performed yearly in all male CAH patients.

Non syndromic monogenic obesity is a rare cause of early onset severe obesity in the childhood period. This form may not be distinguishable from other forms of severe obesity without genetic analysis, particularly if patients do not exibit any physical abnormalities or developmental delay. The aim of this study was to screen 41 different obesity-related genes in children with non-syndromic early onset severe obesity. Children with severe (body mass index-standard deviation score >3) and early onset (<7 years) obesity were screened by next-generation sequencing based, targeted DNA custom panel for 41 known-obesity-related genes and the results were confirmed by Sanger technique. Six novel variants were identified in five candidate genes in seven out of 105 children with severe obesity; two in SIM1 (p.W306C and p.Q36X), one in POMC (p.Y160H), one in PCSK1 (p.W130G fs Ter8), two in MC4R (p.D126E) and one in LEPR (p.Q4H). Additionally, two previously known variations in MC4R were identified in four patients (p.R165W in three, and p.V166I in one). We identified six novel and four previously described variants in six obesity-related genes in 11 out of 105 childrens with early onset severe obesity. The prevalence of monogenic obesity was 10.4% in our cohort.