[From gene to disease; hypogonatrophic hypogonadism and anosmia: Kallmann's syndrome].

Kallmann's syndrome is a genetic condition characterised by hypogonadotrophic hypogonadism and anosmia; additional neurological and non-neurological symptoms may also occur depending on the specific mode of inheritance. Mode of inheritance can be X-linked (KAL-1), autosomal dominant (KAL-2) or autosomal recessive (KAL-3), although unrelated sporadic cases occur more frequently. The gene responsible for the X-linked form, namely KAL-1, and its encoded protein anosmin-1 have been identified for some time. Very recently the gene responsible for the autosomal dominant form was also identified. KAL-2 is caused by loss-of-function mutations in the gene encoding fibroblast growth-factor receptor-1 (FGFR1).