Open AccessGenetic Factors Explain Variation in the Age at Onset of Psoriasis: A Population-based Twin Study
Author(s) -
Ann Sophie Lønnberg,
Lone Skov,
David L. Duffy,
Axel Skytthe,
Kirsten Ohm Kyvik,
Ole Birger Pedersen,
Simon Francis Thomsen
Publication year - 2016
Publication title -
acta dermato-venereologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.982
H-Index - 83
eISSN - 1651-2057
pISSN - 0001-5555
DOI - 10.2340/00015555-2171
Subject(s) - psoriasis , twin study , danish , medicine , hazard ratio , proportional hazards model , demography , population , age of onset , dizygotic twin , heritability , genetics , biology , confidence interval , dermatology , disease , linguistics , philosophy , environmental health , sociology
The aim of this study was to determine the age at onset of psoriasis in a population-based twin sample. Questionnaire-data in 10,725 twin pairs, 20-71 years of age, from the Danish Twin Registry, was collected, and analysed using survival regression analysis. Median age at onset was 25 and 28 years among women and men, respectively. The correlation between the ages was 0.84 (bootstrap standard error?=?0.044) in monozygotic twin pairs and 0.60 (0.051) in dizygotic twin pairs, permutation p?=?0.001. Age at onset of psoriasis in the index twin did not predict risk of psoriasis in the co-twin, hazard ratio (per year of later onset =?1.01 (0.99-1.03), p?=?0.434. In conclusion, these data support that the age at onset of psoriasis is, in part, an inherited property. Our results do not support that early-onset psoriasis is more genetically determined.