Psoriasis susceptibility locus on 18p revealed by genome scan in Finnish families not associated with PSORS1.
The major susceptibility locus for psoriasis, PSORS1, resides on chromosome 6p and includes the candidate genes HLA-C, HCR, and CDSN. Based on a nationwide collection of psoriasis patients and genotyping for the PSORS1 susceptibility haplotype, we selected for a genome scan nine families who do not show association with PSORS1 to more easily detect minor loci for psoriasis susceptibility. In the genome scan, five loci gave initial evidence of linkage and were studied with a denser marker map. After fine mapping, only one locus on 18p11.23 showed suggestive evidence of linkage (nonparametric multipoint linkage analysis score, 3.58; p = 0.0038). The bootstrapping analysis showed that one large family contributed the majority of the linkage (p = 0.0039), but was supported by other families. Haplotype sharing between the linked families and haplotype association analysis gave additional support for the locus. Further, the 18p locus has shown nominal evidence of linkage with psoriasis in the British population. Taken together, these findings confirm the presence of a minor susceptibility locus for psoriasis on 18p11.
Asumalahti
Kati
K
Department of Medical Genetics, University of Helsinki, Helsinki, Finland.
Laitinen
Tarja
T
Lahermo
Päivi
P
Suomela
Sari
S
Itkonen-Vatjus
Raija
R
Jansen
Christer
C
Karvonen
Jaakko
J
Karvonen
Seija-Liisa
SL
Reunala
Timo
T
Snellman
Erna
E
Uurasmaa
Tutta
T
Saarialho-Kere
Ulpu
U
Kere
Juha
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002874:Chromosome Mapping; D002887:Chromosomes, Human, Pair 18; D005192:Family Health; D005260:Female; D005387:Finland; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D015894:Genome, Human; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011565:Psoriasis / Q000235:genetics*