Evidence for a polygenic contribution to androgenetic alopecia.

Background: Male pattern baldness (androgenetic alopecia, AGA) is a highly heritable trait and the most common form of hair loss in humans. Eight genome-wide significant risk loci for AGA have been identified.

Objectives: To determine whether a polygenic component contributes to the genetic risk for AGA.

Investigation of selected cytokine genes suggests that IL2RA and the TNF/LTA locus are risk factors for severe alopecia areata.

Background: Alopecia areata (AA) is the second most common cause of hair loss in humans, and has a genetically complex inheritance. The hypothesis that AA is autoimmune in nature is supported by previous studies. These report an association with specific HLA alleles, as well as genetic variants of other genes implicated in autoimmunity, such as various cytokine genes.

Six novel susceptibility Loci for early-onset androgenetic alopecia and their unexpected association with common diseases.

Androgenetic alopecia (AGA) is a highly heritable condition and the most common form of hair loss in humans. Susceptibility loci have been described on the X chromosome and chromosome 20, but these loci explain a minority of its heritable variance. We conducted a large-scale meta-analysis of seven genome-wide association studies for early-onset AGA in 12,806 individuals of European ancestry.

Follow-up study of the first genome-wide association scan in alopecia areata: IL13 and KIAA0350 as susceptibility loci supported with genome-wide significance.

Recently, the first genome-wide association study (GWAS) of alopecia areata (AA) was conducted in a North-American sample, and this identified eight susceptibility loci surpassing genome-wide significance. The aim of the present follow-up association analysis was to confirm five of these eight loci (single-nucleotide polymorphisms (SNPs) from the CTLA4, IL-2RA, and HLA regions were not included due to previous own findings) and test 12 other loci from the GWAS, which did not surpass the threshold for genome-wide significance. Twenty-three SNPs from the 17 loci were investigated using a sample of 1,702 Central European AA patients and 1,723 controls.