Genetics of sarcoidosis.
OBJECTIVE
Increased familial occurrences as well as different disease modes in different ethnic groups suggest a genetic influence in sarcoidosis. Also, genetic analyses have revealed a number of chromosomal regions and specific genes associated with sarcoidosis. This review brings up some recent discoveries on the genetic contribution to sarcoidosis.


RESULTS
As a more detailed clinical classification of patients is performed, stronger genetic associations between distinct clinical phenotypes and specific gene variants have been revealed. The strong association between human leucocyte antigen DRB10301/DQB10201 and good prognosis in patients with Löfgren's syndrome is one such recent example. Linkage studies have revealed certain chromosomal regions of interest and furthermore pointed out specific genes of interest, for example, a variant of the butyrophilin-like 2 gene.


CONCLUSIONS
Sarcoidosis is a complex disease which is influenced by a multitude of genes and environmental factors. The strongest genetic associations are found within the human leucocyte antigen region, in which several specific human leucocyte antigen alleles clearly associate with disease risk and phenotype, but additional genes in the same region may turn out to be important as well. Future studies on large, clinically well defined patient cohorts will help to elucidate the genetic impact on sarcoidosis.
Grunewald
Johan
J
Division of Respiratory Medicine, Department of Medicine, Karolinska Institute and Karolinska University Hospital Solna, Stockholm, Sweden. johan.grunewald@ki.se
D000071797:Butyrophilins; D004893:Erythema Nodosum / Q000235:genetics; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000235:genetics; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D017565:Sarcoidosis, Pulmonary / Q000235:genetics*
C408263:BTNL2 protein, human; D000071797:Butyrophilins; D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D008562:Membrane Glycoproteins