Clinical and Genetic Characterization of a Constitutional Delay of Growth and Puberty Cohort.

INTRODUCTION: Constitutional delay of growth and puberty (CDGP) is the most prevalent cause of delayed puberty in both sexes. Family history of delayed puberty (2 or more affected members in a family) has been evidenced in 50-75% of patients with CDGP and the inheritance is often consistent with autosomal dominant pattern, with or without complete penetrance. However, the molecular basis of CDGP is not completely understood. OBJECTIVE: To characterize the clinical and genetic features of a CDGP cohort. METHODS: Fifty-nine patients with CDGP (48 boys and 11 girls) underwent careful and long-term clinical evaluation. Genetic analysis was performed using a custom DNA target enrichment panel designed to capture 36 known and candidate genes implicated with pubertal development. RESULTS: All patients had spontaneous or induced pubertal development (transient hormonal therapy) prior to 18 years of age. The mean clinical follow-up time was 46 ± 28 months. Male predominance (81%), short stature (91%), and family history of delayed puberty (59%) were the main clinical features of this CDGP -cohort. Genetic analyses revealed 15 rare heterozygous missense variants in 15 patients with CDGP (25%) in seven different genes (IGSF10, GHSR, CHD7, SPRY4, WDR11, SEMA3A,and IL17RD). IGSF10 and GHSR were the most prevalent affected genes in this group. CONCLUSIONS: Several rare dominant variants in genes implicated with GnRH migration and metabolism were identified in a quarter of the patients with familial or sporadic CDGP, suggesting genetic heterogeneity in this frequent pediatric condition.

Molecular and Genetic Aspects of Congenital Isolated Hypogonadotropic Hypogonadism.

Congenital isolated hypogonadotropic hypogonadism (IHH) is a clinically and genetically heterogenous disorder characterized by abnormal synthesis, secretion, or action of gonadotropin-releasing hormone, a key hypothalamic decapeptide that orchestrates the reproductive axis. Several modes of inheritance have been identified. A growing list of causative genes has been implicated in the molecular pathogenesis of syndromic and nonsyndromic IHH, largely contributing for better understanding the complex neuroendocrine control of reproduction. This article summarizes the great advances of molecular genetics of IHH and pointed up the heterogeneity and complexity of the genetic basis of this condition.

HRPT2 gene alterations in ossifying fibroma of the jaws.

Ossifying fibroma (OF) is a benign neoplasm related to bone characterized by a progressive enlargement of the affected jaw. Recently, the candidate tumor suppressor gene HRPT2 was identified and alterations in this gene were related with the Hyperparathyroidism-jaw tumor syndrome that is characterized by parathyroid adenoma or carcinoma, fibro-osseous lesions (mainly OF) of the jaws, and renal lesions. The purpose of the present study was to evaluate the HRPT2 gene in OF. Tumour and blood samples were obtained from 3 patients with OF and one with juvenile ossifying fibroma (JOF). The results demonstrated three novel mutations in two out of three genotyped OF's. Interestingly, one of these patients showed a germ-line mutation after blood analysis. RT-PCR amplification was performed to analyze HRPT2 mRNA expression and only wild-type HRPT2 transcript was found in all tumours. Investigation of the parafibromin protein by immunohistochemistry showed a similar pattern of immunolocalization with strong nuclear and cytoplasmic staining in all cases. In conclusion, the present study shows for the first time mutations of HRPT2 gene in OF and suggests that OF may arise due to haploinsufficiency of the HRPT2 gene.