Detection of carriers for X-linked ichthyosis by Southern blot analysis and identification of one family with a de novo mutation.
Scaling in patients with recessive X-linked ichthyosis is caused by lack of activity of the enzyme steroid sulfatase. In approximately 90% of kindreds, this lack is the result of a DNA deletion large enough to eliminate the coding region completely. We have used Southern blot hybridization of DNA isolated from peripheral blood leukocytes to measure gene dosage of the steroid sulfatase gene. This readily detects a half-normal dosage in women who are carriers and therefore can be used to diagnose the carrier status of female relatives of 90% of patients with the disease. We have found one family in whom the deletion arose on an allele inherited from the proband's clinically normal maternal grandfather.
Bonifas
J M
JM
Department of Dermatology, San Francisco General Hospital Medical Center, California.
Epstein
E H
EH
D001192:Arylsulfatases / Q000235:genetics; D015139:Blotting, Southern; D004247:DNA / Q000032:analysis; D015342:DNA Probes; D005167:Factor VII / Q000235:genetics; D005260:Female; D006580:Genetic Carrier Screening / Q000379:methods*; D008040:Genetic Linkage; D006801:Humans; D007057:Ichthyosis / Q000235:genetics*; D008297:Male; D009154:Mutation; D043266:Steryl-Sulfatase; D014960:X Chromosome
D015342:DNA Probes; D005167:Factor VII; D004247:DNA; D001192:Arylsulfatases; D043266:Steryl-Sulfatase