The second form refers to congenital hypogonadotropic hypogonadism, which is characterized by decreased levels of LH and FSH, as well as small testes. The third category encompasses cases with an ambiguous presentation of testicular dysfunction, characterized by disparate hormone and testicular volume profiles, including elevated FSH with normal testicular size, normal FSH with testicular atrophy, or normal FSH with preserved testicular volume. This evidence concerns the gene BRD2 and congenital hypogonadotropic hypogonadism.