Endocrine Abstracts

Introduction: To date, several mutations have been identified as the underlying cause of hypogonadotropic hypogonadism. However, they account for a small minority of cases, suggesting that other genes play a significant role in the pathogenesis. The aim of the present study was to examine the prevalence of KAL1, GnRH1, GnRHR, PROK2 and PROKR2 mutations. Because it has several advantages over traditional screening methods, multiplex ligation dependent probe amplification (MLPA) was used to identify genomic rearrangements.

Description of methods/results: Eighty six hypogonadal young male patients (76 with nIHH and 10 with KS) and 95 age-matched, healthy control subjects participated in our study. Following DNA denaturation, hybridization of MLPA probes, ligation reaction, PCR reaction and separation of amplification products by electrophoresis data were evaluated using Genotyper 2.0 Software. Peak areas for each exon were converted into an Excel file and the relative DNA copy number ratios of each fragment were compared to the same fragments from 2 to 3 healthy subjects.

Result: Using MLPA for the described genes, seven mutations were present in 6 of the 86 patients with IHH. three patients with KS had heterozygous deletions in exon 9 of the KAL1 gene, one of whom also carried a duplication in exon 11 of the same gene, and 3 patients with nIHH possessed a duplication in exon 3 of the PROK2 gene, a heterozygous deletion in exon 1 and a duplication in exon 2 of the GnRHR gene, respectively. No abnormalities were identified in the healthy control individuals.

Conclusion: Defining the genetic basis of disease is essential to improve our understanding of this complex disorder, and can be useful for genetic counseling and for directing therapy. For detecting genomic deletions and duplications, MLPA is advantageous over the traditional methods because of its simplicity, relatively low cost and efficiency.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.