Delayed Puberty and Hypogonadism Caused by Mutations in the Follicle-Stimulating Hormone β-Subunit Gene

The pituitary gonadotropins luteinizing hormone and follicle-stimulating hormone (FSH) regulate the production of sex steroids necessary for pubertal development and fertility. Inherited genetic defects that cause hypogonadism have been identified at multiple levels of the hypothalamic–pituitary–gonadal axis.1 They include Kallmann's syndrome, which is caused by mutations in the KAL gene,2 and X-linked adrenal hypoplasia, which is caused by mutations in the DAX-1 gene.3 Both cause deficiency of hypothalamic gonadotropin-releasing hormone, and DAX-1 mutations also cause a defect in the production of gonadotropins by the pituitary.4 A homozygous mutation in the gene for the β-subunit of luteinizing hormone has been reported . . .