Sarcoidosis and genetics

Familial features of sarcoidosis and observations in monozygotic twins affected by the condition suggest the presence of a genetic predisposition. Various genetic associations have been described with genes coding for proteins involved in immune regulation in particular at the level of interaction between T-lymphocyte and antigen presenting cell. We review the various genetic targets described with techniques ranging from classic human lymphocyte antigen genotype to genome wide linkage scans. The 6p21 region has been highlighted, which includes relevant genes such as MHC class II, BTNL2 and TNF alpha. These studies show that the genetics of sarcoidosis are complex, that patient sub-groups exist, which may explain some of heterogeneity in the results of genetic studies and that the interactions between genetic and environmental factors remains to be elucidated. (C) 2011 SPLF. Published by Elsevier Masson SAS. All rights reserved.