Genetic findings in short Turkish children born to consanguineous parents

IntroductionThe diagnostic yield of genetic analysis in the evaluation of children with short stature depends onassociated clinical characteristics, but the additional effect of parental consanguinity has not beenwell documented.MethodsThis observational case series of 42 short children from 34 consanguineous families was collected bysix referral centres of paediatric endocrinology (inclusion criteria: short stature and parentalconsanguinity). In eighteen patients (12 families, Group 1), the clinical features suggested a specificgenetic defect in the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis, and a candidategene approach was used. In others (Group 2) a hypothesis-free approach was chosen (gene panels,microarray analysis, and whole-exome sequencing), further subdivided into 11 patients with severeshort stature (height <-3.5 SDS) and microcephaly (head circumference <-3.0 SDS) (group 2a), 10patients with syndromic short stature (group 2b) and were 3 patients with nonspecific isolated GHdeficiency (group 2c).ResultsIn all 12 families from group 1, (likely) pathogenic variants were identified in GHR, IGFALS, GH1, andSTAT5B. In 9/12 families from group 2a, variants were detected in PCNT, SMARCAL1, SRCAP, WDR4and GHSR. In 5/9 families from group 2b, variants were found in TTC37, SCUBE3, NSD2, RABGAP1,and 17p13.3 microdeletions. In group 2c no genetic cause was found. Homozygous, compoundheterozygous and heterozygous variants were found in 21, 1 and 4 patients, respectively.ConclusionGenetic testing in short children from consanguineous parents has a high diagnostic yield, especiallyin cases of severe GH deficiency or insensitivity, microcephaly, and syndromic short stature

POU6F2 mutation in humans with pubertal failure alters GnRH transcript expression

Idiopathic hypogonadotropic hypogonadism (IHH) is characterized by the absence of pubertal development and subsequent impaired fertility often due to gonadotropin-releasing hormone (GnRH) deficits. Exome sequencing of two independent cohorts of IHH patients identified 12 rare missense variants in POU6F2 in 15 patients. POU6F2 encodes two distinct isoforms. In the adult mouse, expression of both isoform1 and isoform2 was detected in the brain, pituitary, and gonads. However, only isoform1 was detected in mouse primary GnRH cells and three immortalized GnRH cell lines, two mouse and one human. To date, the function of isoform2 has been verified as a transcription factor, while the function of isoform1 has been unknown. In the present report, bioinformatics and cell assays on a human-derived GnRH cell line reveal a novel function for isoform1, demonstrating it can act as a transcriptional regulator, decreasing GNRH1 expression. In addition, the impact of the two most prevalent POU6F2 variants, identified in five IHH patients, that were located at/or close to the DNA-binding domain was examined. Notably, one of these mutations prevented the repression of GnRH transcripts by isoform1. Normally, GnRH transcription increases as GnRH cells mature as they near migrate into the brain. Augmentation earlier during development can disrupt normal GnRH cell migration, consistent with some POU6F2 variants contributing to the IHH pathogenesis

Volume CXIV, Number 4, November 7, 1996

Objective: 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.Methods: 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.Results: 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%.Conclusion: 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 lifespa

Gonadal malignancy risk and prophylactic gonadectomy in disorders of sexual development

Disorders of sex development (DSD) are a generic definition including any problem noted at birth where the genitalia are atypical in relation to the chromosomes or gonads. The most important clinical problems in DSD comprise physical and psychological disturbances and the risk of gonadal tumor development. Germ cell tumor risk is lowest (<5%) in patients with defects in androgene action or synthesis (such as complete androgen insensitivity syndrome, 5 alpha-reductase deficiency), whereas the highest risk (15%-60%) is observed in 46, XY gonadal dysgenesis. The presence of Y chromosomal material in the karyotype increases the risk for the development of gonadal tumors. The reported age of tumor development varies based on the etiology of DSD (gonadal dysgenesis, androgen insensitivity syndrome, androgen synthesis defects, mixed gonadal dysgenesis, etc.). In the past, early gonadectomy was recommended for all cases of 46, XY DSD, however, according to current approaches, gonadal tumor risk is predicted based on the molecular diagnosis and the timing of the gonadectomy depends on the result of molecular analysis. Until now, optimal protocol in the management of DSD is still controversial. In addition to that, safe and well-accepted guidelines are needed. There is limited number of prospective studies on timing of a gonadectomy in childhood and adolescence. Therefore, evidence-based data on timing and indications of gonadectomy in patients with DSD are needed. In this review, recent data regarding gonadal malignancy risk in DSD and recommendations on timing of gonadectomy are presented

Low serum nesfatin-1 levels may be a contributing factor for monogenic obesity due to prohormone convertase 1 deficiency

Leptin, leptin receptor, proopiomelanocortin, prohormone convertase 1, melanocortin-4 receptor, melanocortin-3 receptor, brain-derived neurothrophic factor, neurotrophic tyrosine receptor kinase type 2, and single minded 1 genes, which are the genes that have been shown to cause monogenic obesity, are related to the leptin-melanocortin system. Congenital prohormone convertase I deficiency is a very rare syndrome characterized by early-onset obesity, small intestinal dysfunction, impaired glucose homeostasis, and disrupted prohormone processing. Obesity phenotype seen in this syndrome is known to be due to reduced melanocortin signaling in the hypothalamus which arises as a result of impaired processing of proopiomelanocortin. However, prohormone convertase 1 cleaves a number of other neuropeptides involved in feeding behavior and impaired cleavage of these neuropeptides, particularly NUCB2/nesfatin, may be a contributing factor for development of obesity in these cases. Until now, in prohormone convertase 1 deficient patients, low serum nesfatin-1 levels have not been mentioned to be a possible cause of obesity, we suggest that in these patients low levels of anorexigenic peptid nesfatin-1 might be another facilitating factor for development of obesity. (C) 2013 Elsevier Ltd. All rights reserved

Maturity-onset diabetes of the young (MODY): an update

Maturity-onset diabetes of the young (MODY) is a group of monogenic disorders characterized by autosomal dominantly inherited non-insulin dependent form of diabetes classically presenting in adolescence or young adults before the age of 25 years. MODY is a rare cause of diabetes (1% of all cases) and is frequently misdiagnosed as Type 1 diabetes (T1DM) or Type 2 diabetes (T2DM). A precise molecular diagnosis is essential because it leads to optimal treatment of the patients and allows early diagnosis for their asymptomatic family members. Mutations in the glucokinase (GCK) (MODY 2) and hepatocyte nuclear factor (HNF)1A/4A (MODY 3 and MODY 1) genes are the most common causes of MODY. GCK mutations cause a mild, asymptomatic, and stable fasting hyperglycemia usually requiring no specific treatment. However, mutations in the HNF1A and HNF4A cause a progressive pancreatic beta-cell dysfunction and hyperglycemia that can result in microvascular complications. Sulfonylureas are effective in these patients by acting on adenosine triphosphate (ATP)-sensitive potassium channels, although insulin therapy may be required later in life. Mutations in the HNF1B (MODY 5) is associated with pancreatic agenesis, renal abnormalities, genital tract malformations, and liver dysfunction. Compared to MODY 1, 2, 3, and 5, the remaining subtypes of MODY have a much lower prevalence. In this review, we summarize the main clinical and laboratory characteristics of the common and rarer causes of MODY

Subclinical hypothyroidism in childhood and adolescense

WOS: 000345022900005PubMed ID: 25153584Subclinical hypothyroidism (SH) is defined as a serum thyroid-stimulating hormone (TSH) level above the reference range with normal serum free thyroxin (sT4) and free triiodothyronine (sT3) levels. The prevalence of SH in children and adolescents is reported between 1.7% and 9.5%. Hashimoto's thyroiditis is the most prevalent cause of SH in children. Although it has been suggested that SH is entirely an asymptomatic laboratory diagnosis, typical hypothyroid symptoms as well have been reported in some patients. Results of the adult studies on SH revealed that SH had unfavorable effects on cardiovascular system (atherosclerosis); metabolic parameters (dyslipidemia, insulin resistance, etc.); neuromuscular system; and cognitive functions in the long term. The number of studies investigating the effect of childhood SH on growth, bone maturation, lipid parameters, carbohydrate metabolism, neuromuscular system, and cognitive and cardiac function is limited. Knowledge about the natural history of SH is unclear even though there are numerous studies upon this subject. In children and adults, treatment of SH with L-T-4 is still a matter of debate, and there is no consensus on this issue yet

46,XX Male Disorder of Sexual Development: A Case Report

The main factor influencing sex determination of an embryo is the sex-determining region Y (SRY), a master regulatory gene located on the Y chromosome. The presence of SRY causes the bipotential gonad to differentiate into a testis. However, some individuals carry a Y chromosome but are phenotypically female (46, XY females) or have a female karyotype but are phenotypically male (46, XX males). 46, XX male is rare (1: 20 000 in newborn males), and SRY positivity is responsible for this condition in approximately 90% of these subjects. External genitalia of 46, XX SRY-positive males appear as normal male external genitalia, and such cases are diagnosed when they present with small testes and/or infertility after puberty. Herein, we report an adolescent who presented with low testicular volume and who was diagnosed as a 46, XX male. SRY positivity was demonstrated in the patient by fluorescence in situ hybridization method

Epidemiology, Classification and Management of Undescended Testes: Does Medication Have Value in its Treatment?

Genetic, hormonal, and anatomical factors are believed to be involved in the etiology of undescended testes. Due to increased risk of infertility, testicular cancer, torsion and/or accompanying inguinal hernia (>90%) as well as cosmetic concerns, all these patients require treatment. In this review paper, we aimed to evaluate the success rates of treatment modalities used in undescended testes, beginning from 1930 to the present, and to draw attention to the possible risks and benefits and also the efficacy of hormonal therapy in the management of the disorder, which is still a controversial issue. Hormonal therapy may lead to penile growth, painful erection, and behavioral changes while on treatment. In recent years, it has been reported that human chorionic gonadotropin (hCG) treatment was associated with interstitial edema due to increased vascular permeability, inflammation-like changes, and several adverse effects on germ cells by increasing pressure and apoptotic process. It has also been reported that LHRH analogues have positive effects on germ cells by increasing fertility in patients undergoing unilateral or bilateral orchiopexy. In some studies, the success rate of hCG treatment was reported to be higher following buserelin. In some other studies, hCG treatment was recommended before orchiopexy to reduce the risk for surgical ischemia. There are a limited number of randomized controlled studies, so evidence showing the efficacy of hormonal therapy is insufficient. According to the 2007 Consensus Report of Nordic countries, it is recommended that surgery is the first-line treatment modality in undescended testes and that it should be performed by pediatric surgeons and urologists at the age of 6-12 months

Clinical and diagnostic characteristics of hyperprolactinemia in childhood and adolescence

WOS: 000316895000001PubMed ID: 23327784Pituitary adenoma is the most common cause of hyperprolactinemia, which is a rare endocrine disorder encountered in pediatric patient care. Epidemiological and clinical information about hyperprolactinemia in childhood and adolescence is limited. Clinical signs of hyperprolactinemia are very heterogeneous. In girls, disturbances in menstrual function and galactorrhea may be seen, whereas in boys, headache, visual disturbances, delayed pubertal development and hypogonadism are often present. Owing to the ease of ordering a serum prolactin measurement, an evidence-based, cost-effective approach to the management of this endocrine disorder is required. Before a diagnosis of hyperprolactinemia is made, drug use, renal insufficiency, hypothyroidism, and parasellar tumors should be excluded. The main objectives of treatment are normalization of prolactin level, adenoma shrinkage, and recovery from clinical signs related to hyperprolactinemia. In patients with microadenoma, invasive or non-invasive macroadenoma, and even in patients with visual field defects, dopamine agonists are the first-line treatment. Surgical treatment is indicated in patients who are unresponsive or intolerant to medical treatment or who have persistent neurological signs. Radio therapy should be considered as a supportive treatment for patients in whom surgery fails or medical response is not achieved