The absence of disease-specific polymorphisms within the HLA-B51 gene that is the susceptible locus for Behçet's disease.
Behçet's disease is known to be associated with HLA-B51 in many different populations. Genetic evidence supports that the susceptible gene for Behçet's disease is the HLA-B51 allele at the HLA-B locus. This study was aimed to determine the HLA-B51 nucleotide sequence variation in three Behçet's disease patients and three healthy controls in order to elucidate if any disease specific mutations or polymorphisms may exist in the HLA-B51 gene of patients. Long-range polymerase chain reaction (PCR) was first carried out to give a PCR-amplified product of 9.5 kb which was then used as a template for nested PCR to give a final amplified product of 4.2 kb. This final product containing the 1.3-kb promoter/enhancer region and the entire HLA-B gene except for a 363-bp 3' terminal end segment encoding the 3' untranslated region was subcloned by the BP cloning technique and sequenced. The sequencing results showed that all the patients possessed the HLA-B*51011 allele, and there were no differences in the exonic nucleotide sequences between the three Behçet's disease patients and the three healthy controls. The HLA-B*51011 intronic and promoter/enhancer nucleotide sequences from the three patients had 22 single nucleotide polymorphisms (SNPs), a single insertion of 6 bp and a single deletion of 2 bp. On the other hand, the three healthy controls had 24 SNPs in their intronic and promoter/enhancer regions. However, none of these polymorphisms in the patients were specific for the disease. Therefore, these results clearly demonstrate that the HLA-B exonic sequence that encodes the HLA-B51 allele is the real pathogenic factor in Behçet's disease.
Sano
K
K
Department of Genetic Information, Division of Molecular Life Science, Tokai University School of Medicine, Bohseidai, Isehara, Kanagawa, Japan.
Yabuki
K
K
Imagawa
Y
Y
Shiina
T
T
Mizuki
N
N
Ohno
S
S
Kulski
J K
JK
Inoko
H
H
D024506:5' Flanking Region / Q000235:genetics; D001528:Behcet Syndrome / Q000235:genetics* / Q000276:immunology*; D004742:Enhancer Elements, Genetic / Q000235:genetics; D005091:Exons; D020022:Genetic Predisposition to Disease; D015235:HLA-B Antigens / Q000235:genetics*; D059949:HLA-B51 Antigen; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics; D017422:Sequence Analysis, DNA
D015235:HLA-B Antigens; D059949:HLA-B51 Antigen