Analysis of an interstitial deletion in a patient with Kallmann syndrome, X-linked ichthyosis and mental retardation.
الكلمات الدالة
نبذة مختصرة
Contiguous gene syndromes are an interesting clinical phenomenon, resulting from interstitial or terminal deletions of several adjacent genes. The phenotype results in a combination of two or more monogenic disorders and relates clinical findings to corresponding genotypes. We present the case of a male patient with Kallmann syndrome (KS), X-linked ichthyosis (XLI) and X-linked mental retardation (MRX). He was referred at the age of 15.4 years for delayed puberty and obesity. He had a previous history of pyloric stenosis, bilateral orchidopexy and surgical correction of a pes equinovarus adductus. On physical examination, generalised ichthyosis and hypoplastic external genitalia were found. KS was evident with hypogonadotropic hypogonadism, hyposmia and a hypoplastic anlage of the olfactory tract in magnetic resonance imaging. Lipoprotein electrophoresis, and lack of steroid sulfatase and arylsulfatase-C activity in leucocytes confirmed XLI. DNA investigation established an interstitial deletion in Xp22.3 involving the Kallmann (KAL) gene, the steroid sulfatase (STS) gene and a putative mental retardation locus (MRX). The novel MRX locus maps to a 1-Mb region between DXS1060 and GS1.