Kallmann’s syndrome

Abstract

Kallmann syndrome (KS) is a genetic disorder characterized by the association of congenital hypogonadotropic hypogonadism and a total or partial lack of sense of smell. KS is due to the deficiency of gonadotropin-releasing hormone (GnRH), with hypoplasia or aplasia of the olfactory bulbs. Though KS occurs in both male and female, it is commoner in males. An estimated prevalence of 1/8,000 males and 1/40,000 females is reported, but is probably underestimated. KS presents with both reproductive and nonreproductive symptoms. Not all symptoms will appear in every case of KS/HH, not even amongst family members. KS is a congenital condition, and therefore exists from birth. However, the genetic basis of these conditions is not fully understood. KS can be inherited through generations, but it is sometimes difficult to predict if this will occur. The diagnosis is often one of exclusion found during the evaluation of a delayed puberty. Differential diagnosis include other forms of hypogonadotrophic hypogonadism and a normal constitutional delay of puberty. The main laboratory findings include low serum testosterone and low levels of the LH and FSH in men, and low serum oestrogen and low levels of LH and FSH in women. Hormonal replacement therapy is used to induce puberty, and later, fertility. There is currently no treatment for anosmia. KS is not a life threatening condition. With hormonal treatment, puberty occurs in all patients. Fertility, when desired, is achieved in most cases but cryptorchidism not corrected early in life has a poor prognosis.