RESUMO
Isolated 17,20-lyase deficiency (ILD) is a partial form of 17α-hydroxylase/17,20-lyase deficiency that typically presents with infertility and lack of pubertal development. Successful live births have been achieved using assisted reproductive techniques. We present a case of spontaneous pregnancy in an 18-year-old female with ILD without reproduction treatments or glucocorticoid use. She presented to our clinic with absence of pubarche and oligomenorrhea and had typical external genitalia and complete breast development. Follicular phase progesterone and estradiol were within reference values, and androgen levels were undetectable. Corticosterone was increased, and cortisol responded partially to the ACTH-stimulation test. This profile raised a suspicion for ILD, which was confirmed by the finding of the homozygous p.R347H variant in the CYP17A1 gene. Sex steroid replacement and glucocorticoid use during stress were prescribed. She returned 2 years later 20 weeks pregnant. Her gestation was uneventful, and a full-term healthy male was born. This phenomenon could be partially explained by sufficient estrogen synthesis via residual 17,20-lyase enzymatic activity. Intermittent estradiol use may have favored uterine development and fine-tuned the pituitary-gonadal axis rhythm. Normal progesterone levels may have permitted an adequate endometrial "implantation window" without glucocorticoid use. Finally, elevated corticosterone may have compensated for the partial cortisol deficiency.
RESUMO
BACKGROUND: Adrenal hypoplasia congenita (AHC) is an X-linked disorder that affects the adrenal cortex and hypothalamus-pituitary-gonadal axis (HPG), leading to primary adrenocortical insufficiency (PAI) and hypogonadotropic hypogonadism. AHC is caused by a mutation in the DAX-1 gene (NR0B1). More commonly, this disease is characterized by early-onset PAI, with symptoms in the first months of life. However, a less severe phenotype termed late-onset AHC has been described, as PAI signs and symptoms may begin in adolescence and adulthood. Here we describe a family report of a novel mutation within NR0B1 gene and variable reproductive phenotypes, including spontaneous fertility, in a very late-onset X-linked AHC kindred. CASE PRESENTATION: Three affected maternal male relatives had confirmed PAI diagnosis between 30 y and at late 64 y. The X-linked pattern has made the endocrinology team to AHC suspicion. Regarding the HPG axis, all males presented a distinct degree of testosterone deficiency and fertility phenotypes, varying from a variable degree of hypogonadism, oligoasthenoteratozoospermia to spontaneous fertility. Interestingly, the other five maternal male relatives unexpectedly died during early adulthood, most likely due to undiagnosed PAI/adrenal crisis as the probable cause of their premature deaths. Sequencing analysis of the NR0B1 gene has shown a novel NR0B1 mutation (p.Tyr378Cys) that segregated in three AHC family members. CONCLUSIONS: NR0B1 p.Tyr378Cys segregates in an AHC family with a variable degree of adrenal and gonadal phenotypes, and its hemizygous trait explains the disease in affected family members. We recommend that NR0B1 mutation carriers, even those that are allegedly asymptomatic, be carefully monitored while reinforcing education to prevent PAI and consider early sperm banking when spermatogenesis still viable.
Assuntos
Insuficiência Adrenal/genética , Insuficiência Adrenal/patologia , Receptor Nuclear Órfão DAX-1/genética , Fertilidade , Doenças Genéticas Ligadas ao Cromossomo X/genética , Doenças Genéticas Ligadas ao Cromossomo X/patologia , Reprodução , Adulto , Idade de Início , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Fenótipo , PrognósticoRESUMO
Congenital hypogonadotrophic hypogonadism (CHH) is a challenging inherited endocrine disorder characterised by absent or incomplete pubertal development and infertility as a result of the low action/secretion of the hypothalamic gonadotrophin-releasing hormone (GnRH). Given a growing list of gene mutations accounting for CHH, the application of massively parallel sequencing comprises an excellent molecular diagnostic approach because it enables the simultaneous evaluation of many genes. The present study proposes the use of whole exome sequencing (WES) to identify causative and modifying mutations based on a phenotype-genotype CHH analysis using an in-house exome pipeline. Based on 44 known genes related to CHH in humans, we were able to identify a novel homozygous gonadotrophin-releasing hormone receptor (GNRHR) p.Thr269Met mutant, which segregates with the CHH kindred and was predicted to be deleterious by in silico analysis. A functional study measuring intracellular inositol phosphate (IP) when stimulated with GnRH on COS-7 cells confirmed that the p.Thr269Met GnRHR mutant performed greatly diminished IP accumulation relative to the transfected wild-type GnRHR. Additionally, the proband carries three heterozygous variants in CCDC141 and one homozygous in SEMA3A gene, although their effects with respect to modifying the phenotype are uncertain. Because they do not segregate with reproductive phenotype in family members, we advocate they do not contribute to CHH oligogenicity. WES proved to be useful for CHH molecular diagnosis and reinforced its benefit with respect to identifying heterogeneous genetic disorders. Our findings expand the GnRHR mutation spectrum and phenotype-genotype correlation in CHH.