An Effective Outcome Despite Delayed Treatment Initiation in a Female With Kallmann Syndrome: A Case Report

Kallmann syndrome (KS) is an idiopathic hypogonadotropic hypogonadism with anosmia due to isolated gonadotropin-releasing hormone deficiency. In females, the diagnosis often occurs around age 15 due to primary amenorrhea, prompting hormone replacement therapy (HRT) initiation. However, limited data exists on the effectiveness of delayed HRT in females with KS. Here, we describe a case involving a female with KS who began treatment at the age of 27. Following HRT initiation, the patient showed increases in uterine size, bone mineral density, and growth of breasts over a two-year period. Delayed diagnosis of KS in females, as in this case, is extremely rare, and this case demonstrates two important clinical issues. First, HRT can still be effective in females with KS even if treatment initiation is delayed, and, second, therapeutic benefits become apparent within two years following initiation of treatment. These findings may be applicable to other patients with congenital hypogonadotropic hypogonadism whose treatment initiation was delayed.