X/Y translocation in a family with X-linked ichthyosis, chondrodysplasia punctata, and mental retardation: DNA analysis reveals deletion of the steroid sulphatase gene and translocation of its Y pseudogene.
We describe a family with two male members showing an X/Y translocation (karyotype: 46,Y,der(X)t(X;Y)(p22;q11]. At physical examination both patients showed ichthyosis, mental retardation and dysmorphic features. Chondrodysplasia punctata and short stature were present in one case. Direct DNA analysis, using a steroid sulphatase cDNA probe, was performed in one patient, his mother and sister, both carriers of the translocation. We found that the translocated region of the Y chromosome includes the steroid sulphatase pseudogene. These results suggest that in our patients the X/Y translocation may be derived from a recombinational event between homologous regions located on the short arm of the X chromosome and the long arm of the Y chromosome. Clinical and molecular studies on the present family add further information for the construction of a tentative physical map of the distal Xp.
Ballabio
A
A
Department of Paediatrics, University of Naples, Italy.
Parenti
G
G
Carrozzo
R
R
Coppa
G
G
Felici
L
L
Migliori
V
V
Silengo
M
M
Franceschini
P
P
Andria
G
G
D002648:Child; D002806:Chondrodysplasia Punctata / Q000235:genetics*; D002874:Chromosome Mapping; D004247:DNA / Q000235:genetics*; D008040:Genetic Linkage; D006801:Humans; D007057:Ichthyosis / Q000235:genetics*; D008607:Intellectual Disability / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D010375:Pedigree; D043266:Steryl-Sulfatase; D013429:Sulfatases / Q000235:genetics*; D014178:Translocation, Genetic; D014960:X Chromosome; D014998:Y Chromosome
D004247:DNA; D013429:Sulfatases; D043266:Steryl-Sulfatase