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Contiguous gene syndrome due to deletion of the first three exons of the Kallmann gene and complete deletion of the steroid sulphatase gene
Author(s) -
MayaNúñez Guadalupe,
CuevasCovarrubias Sergio,
Carlos Zenteno Juan,
UlloaAguirre Alfredo,
KofmanAlfaro Susana,
Pablo Méndez Juan
Publication year - 1998
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1046/j.1365-2265.1998.00406.x
Subject(s) - kallmann syndrome , steroid sulfatase , anosmia , ichthyosis , endocrinology , biology , exon , hypogonadotrophic hypogonadism , medicine , hypogonadotropic hypogonadism , genetics , hyposmia , gene , steroid , disease , covid-19 , hormone , infectious disease (medical specialty)
OBJECTIVE Large terminal or interstitial deletions of the 22.3 region on the short arm of the X chromosome cause contiguous gene syndromes. Kallmann syndrome (hypogonadotrophic hypogonadism with anosmia or hyposmia) associated with X‐linked ichthyosis, due to a contiguous gene syndrome, is an uncommon finding. Genetic defects have been demonstrated in the Xp22.3 region, explaining the presence of one or both entities in affected individuals. In this report we describe the molecular findings of a patient with Kallmann syndrome and X‐linked ichthyosis. PATIENT A 20‐year‐old subject with hypogonadism, anosmia and generalized ichthyosis was studied endocrinologically, biochemically and molecularly. MEASUREMENTS Levels of LH, FSH, GH, testosterone, oestradiol and cortisol were determined basally and after specific stimulation tests. Enzymatic activity of steroid sulphatase was measured in leucocytes. Polymerase chain reaction of the 14 exons of the Kallmann gene and of the 5′ and 3′ extremes of the steroid sulphatase gene was performed in genomic DNA. RESULTS A partial deletion from exon 1 to exon 3 of the Kallmann gene, as well as a complete deletion of the steroid sulphatase gene were observed. CONCLUSIONS A patient bearing a contiguous gene syndrome with partial deletion of the Kallmann syndrome gene and complete deletion of the steroid sulphatase gene is described. This is the first time a mutation in the conserved cysteine‐rich N ‐terminal region which corresponds to the whey acidic protein motif of the Kallmann gene has been characterized, thus demonstrating the importance of this specific region for the function of the gene.