Clinical evaluation in isolated hypogonadotrophic hypogonadism (Kallmann syndrome)

Objective: To describe the clinical features, laboratory investigation and treatment of Kallmann syndrome. Design: A retrospective study of patients treated in the Endocrine Clinic of the Royal Children's Hospital and St Vincent's Hospital, Melbourne, between 1984 and 1996. Results: Eleven males and 5 females with Kallmann syndrome are described. Their ages at presentation ranged from one week to 21 years. Presenting symptoms were micropenis, small testes, anosmia and delayed puberty. Fifty-six percent (9/16) had a family history of either anosmia or infertility. The features of Kallmann syndrome are variable. We have described unilateral renal aplasia, coloboma of iris, deafness, midline anomalies, oculomotor apraxia and Moebius anomalad as features that were associated with Kallmann syndrome in our group of subjects. One patient diagnosed as having X-linked Kallmann syndrome has previously been shown to have a specific mutation in an intronic sequence adjacent to exon 6. Most patients showed low serum levels of basal gonadotrophins, testosterone or oestrogen, and had a poor response to LHRH stimulation, but two patients showed a pubertal response to LHRH stimulation, and may have a variant form of Kallmann syndrome. Treatment given to these patients included exogenous testosterone or oestrogen for induction of puberty, with appropriate pubertal progress occurring in each patient. Conclusion: The manifestations of Kallmann syndrome vary, depending upon the degree of LHRH deficiency. Therapy should combine exogenons sex hormone replacement and psychological support, with long-term follow-up to ensure maintenance of normal sexual function, normal bone mass and psychosocial outcome, with fertility induction when indicated.