👤 Waljit S Dhillo

Congenital hypogonadotropic hypogonadism (CHH) is a rare and genetically heterogeneous disorder characterized by absent or incomplete puberty due to impaired gonadotropin-releasing hormone (GnRH) function. A subset of individuals with CHH also present with developmental anomalies, including midline defects such as cleft lip and/or palate (CLP). This study investigates the genetic overlap between CHH and CLP. A total of 336 individuals diagnosed with CHH were clinically assessed for associated phenotypes, including CLP. High-throughput sequencing was performed using a targeted gene panel encompassing known CHH- and CLP-related genes. Variants were analyzed and classified according to the American College of Medical Genetics and Genomics (ACMG) criteria for pathogenicity. CLP was present in 21 patients with CHH (6%). Pathogenic or likely pathogenic variants in genes associated with both CHH and CLP-such as FGFR1 and CHD7-were identified in eight individuals. Furthermore, 17% of the patients with CHH without CLP harbored deleterious variants in genes implicated in clefting, including DVL3, PLCB4, NIPBL, and EDNRA. Evidence of digenic inheritance involving both CHH- and CLP-related genes was observed in multiple cases. FGFR1 variants were the most frequently detected and were commonly associated with anosmia and additional developmental anomalies. These findings highlight a genetic and phenotypic continuum between CHH and CLP, underscoring the involvement of shared developmental pathways. The high prevalence of FGFR1 variants in patients with CHH and CLP supports its role as a pleiotropic gene. Understanding the overlapping genetic mechanisms may enhance diagnostic precision and inform personalized management strategies for affected individuals. Show less

BACKGROUNDHypoactive sexual desire disorder (HSDD) is characterized by a persistent deficiency of sexual fantasies and desire for sexual activity, causing marked distress and interpersonal difficulty. It is the most prevalent female sexual health problem globally, affecting approximately 10% of women, but has limited treatment options. Melanocortin 4 receptor (MC4R) agonists have emerged as a promising therapy for women with HSDD, through unknown mechanisms. Studying the pathways involved is crucial for our understanding of normal and abnormal sexual behavior.METHODSUsing psychometric, functional neuroimaging, and hormonal analyses, we conducted a randomized, double-blinded, placebo-controlled, crossover clinical study to assess the effects of MC4R agonism compared with placebo on sexual brain processing in 31 premenopausal heterosexual women with HSDD.RESULTSMC4R agonism significantly increased sexual desire for up to 24 hours after administration compared with placebo. During functional neuroimaging, MC4R agonism enhanced cerebellar and supplementary motor area activity and deactivated the secondary somatosensory cortex, specifically in response to visual erotic stimuli, compared with placebo. In addition, MC4R agonism enhanced functional connectivity between the amygdala and the insula during visual erotic stimuli compared with placebo.CONCLUSIONThese data suggest that MC4R agonism enhanced sexual brain processing by reducing self-consciousness, increasing sexual imagery, and sensitizing women with HSDD to erotic stimuli. These findings provide mechanistic insight into the action of MC4R agonism in sexual behavior and are relevant to the ongoing development of HSDD therapies and MC4R agonist development more widely.TRIAL REGISTRATIONClinicalTrials.gov NCT04179734.FUNDINGThis is an investigator-sponsored study funded by AMAG Pharmaceuticals Inc., the Medical Research Council (MRC) (MR/T006242/1), and the National Institute for Health Research (NIHR) (CS-2018-18-ST2-002 and RP-2014-05-001). Show less