Genetic polymorphisms in the keratin-like S gene within the human major histocompatibility complex and association analysis on the susceptibility to psoriasis vulgaris.
Psoriasis vulgaris is associated with the HLA-Cw6 and Cw7 antigens. However, it has not yet been clarified if the HLA-Cw6 and Cw7 genes themselves are the susceptible gene related to this disease or if it is some other non-HLA gene in a linkage disequilibrium with these HLA-C alleles. The S gene, recently identified in the HLA class I region 160 kb telomeric of HLA-C, encodes a keratin-like protein and is expressed specifically in the granular layer of the epidermis. Therefore, it is tempting to speculate that the S gene is one of the strong candidate genes responsible for the pathogenesis of psoriasis vulgaris. Direct sequencing of the first and second exon of the S gene after polymerase chain reaction (PCR) amplification has allowed the identification of two diallelic polymorphic sites in exon I and seven diallelic polymorphic sites in exon 2, three among which result in amino acid exchanges, a Ser-Phe substitution at amino acid position 186, a Gly-Val substitution at position 393 and a Ser-Leu substitution at position 394. No significant difference in the dimorphic distributions of the S gene was observed between the patients with psoriasis vulgaris and healthy controls, suggesting that the susceptible gene for psoriasis is not the S gene itself.
Ishihara
M
M
Department of Ophthalmology, Yokohama City University School of Medicine, Japan.
Yamagata
N
N
Ohno
S
S
Naruse
T
T
Ando
A
A
Kawata
H
H
Ozawa
A
A
Ohkido
M
M
Mizuki
N
N
Shiina
T
T
Ando
H
H
Inoko
H
H
D004198:Disease Susceptibility; D005805:Genes, MHC Class I / Q000276:immunology*; D005819:Genetic Markers / Q000235:genetics; D015236:HLA-C Antigens / Q000235:genetics; D006801:Humans; D007633:Keratins / Q000235:genetics* / Q000276:immunology*; D018807:Polymorphism, Single-Stranded Conformational; D011565:Psoriasis / Q000235:genetics* / Q000276:immunology*
D005819:Genetic Markers; D015236:HLA-C Antigens; D007633:Keratins