A gene for familial psoriasis susceptibility maps to the distal end of human chromosome 17q
- Univ. of Texas Southwestern Medical Center, Dallas, TX (United States); and others
Psoriasis is a chronic inflammatory dermatosis that affects approximately 2% of the population. A gene for psoriasis susceptibility was localized to the distal region of human chromosome 17q as a result of a genome wide linkage-analysis with polymorphic microsatellites and eight multiply affected psoriasis kindreds. With one large kindred a maximum two-point lod score with D17S784 was 5.70 at 15% recombination. Heterogeneity testing indicated that psoriasis susceptibility in 50% of the families was linked to distal 17q. Susceptibility to psoriasis has repeatedly been found to be associated with HLA-Cw6 and associated HLA alleles. We therefore genotyped the families for loci within and flanking HLA; these included PCR assays for susceptibility alleles. By lod score analysis no evidence of linkage of psoriasis susceptibility to HLA was detected. The distribution of HLA-Cw6 and HLA-Class II alleles showed that HLA-Cw6 was frequent among patients, particularly in 4 of the 5 unlinked families. All affected members of two of these unlinked families carried HLA-Cw6 (empirical P values of 0.027 and 0.004). In 2 other families 4 of 6 and 6 of 7 had HLA-Cw6. In some of these families, an inability to detect linkage to HLA may have been due to the occurrence of multiple haplotypes carrying the psoriasis associated allele, HLA-Cw6. Contrasting with these findings, we observed a lack of association between HLA-Cw6 and psoriasis in the 3 families in which 17q markers were linked to susceptibility. The ability to detect linkage to 17q confirms that some forms of familial psoriasis are due to molecular defects at a single major genetic locus other than HLA.
- OSTI ID:
- 133369
- Report Number(s):
- CONF-941009--
- Journal Information:
- American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: Suppl.3 Vol. 55; ISSN AJHGAG; ISSN 0002-9297
- Country of Publication:
- United States
- Language:
- English
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