Supplementary Material for: Whole Exome Sequencing Revealed a Novel Nonsense Variant in the <b><i>GNRHR</i></b> Gene<b><i></i></b> Causing Normosmic Hypogonadotropic Hypogonadism in a Pakistani Family
2019-04-04T13:49:42Z (GMT) by
<b><i>Background:</i></b> Congenital hypogonadotropic hypogonadism (CHH) is a heterogeneous disorder characterized by delayed or loss of puberty and infertility due to functional deficiency in the hypothalamic gonadotropin-releasing hormone (GnRH). CHH can be classified into 2 subtypes on the basis of olfaction: Kallmann syndrome and normosmic CHH (nCHH). The spectrum of genetic variants causing CHH is continually expanding. Here, we recruited a consanguineous Pakistani family having 2 male and 2 female infertile patients diagnosed with idiopathic nCHH. <b><i>Aims:</i></b> The aim of this study was to investigate the genetic cause of nCHH in the family. <b><i>Methods:</i></b> Clinical and physical analyses were performed for the patients. Genetic analysis was carried out using whole exome and Sanger sequencing. <b><i>Results:</i></b> Clinical and physical investigations confirmed low levels of gonadotropins and failure of secondary sexual development in the patients. Genetic analysis identified a novel nonsense mutation (chr4: g.68619942G>A, c.112C>T, p.Arg38*) in the gonadotropin-releasing hormone receptor gene (<i>GNRHR</i>) recessively co-segregating with nCHH in this family. All the patients are homozygous and their parents are heterozygous carriers, while normal siblings are heterozygous carriers or wild-type for this mutation, indicating that the identified mutation is pathogenic for nCHH in the family. <b><i>Conclusion:</i></b> We report the first homozygous nonsense mutation in the <i>GNRHR</i> gene (chr4: g. 68619942G>A, c.112C>T, p. Arg38*) that is associated with familial nCHH. Hence, our study displayed a good correlation of the genotype and phenotype of nCHH patients.