Genetics

Abstract

There is considerable epidemiological evidence to support the existence of a genetic predisposition to sarcoidosis (McGrath et al. 2001a; Grunewald 2008). For instance, the prevalence, incidence and severity of the disease vary widely between different races. However, sarcoidosis is not due to defects in a single major gene or chemical pathway but instead appears to be a complex/multifactorial disease likely to result from the interaction of environmental factors and multiple genes, some with a major disease effect but many with a relatively minor effect. Genetic factors are also likely to contribute to the wide variety of clinical presentations, progression as well as prognosis observed in sarcoidosis. Indeed, some believe that sarcoidosis may represent a ‘family’ of diseases, including Löfgren’s syndrome, non-resolving/progressive lung disease, and granulomatous uveitis each with potentially distinct genetic associations. In this respect, berylliosis could also be considered as a subset of the broad grouping ‘sarcoidosis’ and almost certainly was historically (Grutters et al. 2003a).