X-linked ichthyosis with hypogonadism: not always Kallmann's syndrome

We describe two males with congenital ichthyosis secondary to steroid sulphatase deficiency who also manifested delayed puberty with biochemical features of hypogonadotrophic hypogonadism. In the first patient a history of cryptorchidism and the clinical findings of anosmia, micropenis and bimanual synkinesis suggested a contiguous gene syndrome, comprising X-linked Kallmann's syndrome and X-linked ichthyosis. An X-Y chromosomal translocation involving the Xp22.3 locus was identified; deletions of the STS locus and of exons 10–14 of the KAL locus were subsequently demonstrated. The second patient was euosmic and, although the STS locus was deleted in association with a pericentric inversion involving Xp22.3, no deletions were detected at the KAL locus. Clinically, he was felt to have constitutionally delayed puberty rather than hypogonadotrophic hypogonadism and this diagnosis was substantiated by his subsequent development.