title: The HLA-C*06 allele as a possible genetic predisposing factor to psoriasis in South Indian Tamils.
abstract: Psoriasis is a multi-factorial heritable prototypical immune-mediated inflammatory disease, characterized by hyperproliferation of keratinocytes in the affected skin. There are no studies till date, to the best of our knowledge, about the association of HLA-C*06, the risk variant in the PSORS 1 susceptibility locus that confers the greatest risk for early onset of psoriasis, with the disease in South Indian Tamil patients with psoriasis. The present study was performed to determine the association of HLA-C*06 with psoriasis in the South Indian Tamil ethnic population. Three hundred and fifty-five cases of psoriasis and 360 healthy controls were included in this case-control study. Severity grading according to psoriasis area severity index (PASI) scoring was done in patients with psoriasis. PCR assays with sequence-specific primers (PCR-SSP) were used for specific detection of HLA-C*06. PCR with analysis of restriction fragment length polymorphism was used to distinguish between patients homozygous and heterozygous for HLA-C*06. We observed that those with the HLA-C*06-positive allele had a 3.5 times higher odds of having psoriasis compared to those without, [p < 0.0001, OR 3.5, 95 % CI (2.59-4.79)]. Among cases of psoriasis, it was noted that there was a significant association of HLA-C*06 positivity with female psoriatics [p = 0.006; OR 2.49 (1.28-4.87)] and early age of onset of psoriasis [p = 0.002; OR 2.04 (1.29-3.20)]. Our results suggest that the HLA-C*06 allele is positively associated with susceptibility to psoriasis, female gender and early onset of psoriasis in South Indian Tamils.
authors.affiliation: Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India.
authors.forename: S
authors.initials: S
authors.lastname: Indhumathi
authors.affiliation: Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India. linkmedha@gmail.com.
authors.forename: Medha
authors.initials: M
authors.lastname: Rajappa
authors.affiliation: Department of Dermatology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
authors.forename: Laxmisha
authors.initials: L
authors.lastname: Chandrashekar
authors.affiliation: Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, 605006, India.
authors.forename: P H
authors.initials: PH
authors.lastname: Ananthanarayanan
authors.affiliation: Department of Dermatology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
authors.forename: D M
authors.initials: DM
authors.lastname: Thappa
authors.affiliation: Department of Clinical Immunology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India.
authors.forename: V S
authors.initials: VS
authors.lastname: Negi
mesh_terms: D000328:Adult; D000367:Age Factors; D000483:Alleles; D015535:Arthritis, Psoriatic / Q000453:epidemiology / Q000235:genetics; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D015984:Causality; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D015236:HLA-C Antigens / Q000235:genetics*; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D016133:Polymerase Chain Reaction; D011565:Psoriasis / Q000453:epidemiology* / Q000235:genetics*; D012720:Severity of Illness Index; D012737:Sex Factors; D012867:Skin / Q000473:pathology
chemical_list: D015236:HLA-C Antigens
keywords: HLA-C*06 positivity; PCR-SSP; PCR–RFLP; Psoriasis risk; South Indian Tamils