Researchers found a new deletion in the FGFR1 gene that causes a rare condition where the body doesn’t produce enough hormones for puberty and fertility. The study mainly adds to the list of known genetic mutations linked to this condition and does not suggest any new treatments or ways to improve health.

Congenital hypogonadotropic hypogonadism (CHH) is a rare condition characterized by incomplete pubertal development, infertility, and gonadotropin-releasing hormone deficiency, associated with mutations in more than 50 genes. We aimed to conduct an etiological analysis of a CHH Chinese family and summarize the clinical presentations and genetic changes of reported similar cases. Whole-exome sequencing (WES) was performed to identify the molecular cause in the proband. In silico tools were employed to analyze the pathogenicity of the variants. Reported cases with similar clinical features and associated genes were summarized by searching through PubMed/MEDLINE using keywords 'FGFR1,' 'CHH,' and 'Kallmann syndrome (KS).' Genetic analysis revealed a novel likely pathogenic deletion mutation in the FGFR1 gene (NM_023110.3: c.263_264del (Val88Alafs*22)) in a Chinese family exhibiting micropenis and underdeveloped testes. A total of 38 cases with CHH or KS have been previously reported. This study identified a novel FGFR1 deletion variant responsible for CHH, expanding the known mutational spectrum of FGFR1. Typical manifestations include delayed puberty and diverse presentations. The genotype-phenotype correlation in CHH remains unclear and may involve oligogenic effects and epigenetic regulation.