Related Experiment Video
Updated: Jul 10, 2026

Assessing Cellular Target Engagement by SHP2 (PTPN11) Phosphatase Inhibitors
Published on: July 17, 2020
The R620W polymorphism in PTPN22 confers general susceptibility for the development of alopecia areata
1Institute of Human Genetics, University of Bonn, Wilhelmstrasse 31, D-53111 Bonn, Germany. regina.betz@uni-bonn.de
Background:
The functional R620W (c.1858C>T) variant of the protein tyrosine phosphatase nonreceptor 22 gene (PTPN22) has been associated with a variety of autoimmune disorders. A recent study has suggested that R620W also contributes to the severe form of alopecia areata (AA).
Objectives:
We sought to replicate the finding of an association between PTPN22 and severe AA. In addition, we wanted to study the effect of PTPN22 on the general risk to develop AA and on other subtypes of AA (mild AA, early/late age at onset, positive/negative family history).
Methods:
The R620W variant was genotyped in a large case-control sample of Belgian-German origin with 435 patients and 628 controls.
Results:
Significant results were obtained for the overall collective of patients with AA (P=0.007). Subdividing the sample according to severity of AA, family history and age at onset, we detected lowest P-values for patients with the severe form of AA (Pcorr=0.036), with a positive family history (Pcorr=0.042) and with an age at onset
Conclusions:
Our results suggest the R620W variant of PTPN22 as a general risk factor in AA with the strongest effect observed among patients with a severe type of AA, a positive family history or an early onset of disease.
Related Concept Videos
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Pleiotropy
The Retinoblastoma Gene
The first-ever tumor suppressor gene called Rb was identified in retinoblastoma - a rare eye tumor in children. In inherited forms of the disease, a child inherits one defective copy of the Rb gene, which predisposes them to retinoblastoma. However,...
Pharmacogenetics of Phase II Enzymes: N-acetyltransferase, Thiopurine S-methyltransferase, UDP-glucuronosyltransferase
Epistasis
Skin Diseases and Disorders
Gram-positive Staphylococcus spp. and Streptococcus spp. are responsible for many of the most common skin infections. However, many...
