Genetic linkage analysis of multicase families with fibromyalgia syndrome
Yunus MB, Khan MA, Rawlings KK, Green JR, Olson JM, Shah S.
OBJECTIVE: Based on the reports of familial aggregation of fibromyalgia (FM) syndrome, we investigated its possible genetic linkage to HLA by studying multicase families.
METHODS: Forty Caucasian multicase families with a diagnosis of FM (American College of Rheumatology criteria) in 2 or more first degree relatives were investigated. Eighty-five affected and 21 unaffected members of 41 sibships were studied. Depression symptomology was assessed by Zung Self-rating Depression Scale (SDS). HLA typing was performed for A, B, and DRB 1 alleles, and haplotypes were determined with no knowledge of the subject's diagnosis. We investigated genetic linkage to the HLA region by evaluating sibships in multicase families.
RESULTS: Sibship analysis showed significant genetic linkage of FM to the HLA region (p = 0.028). Subgroup analysis was also performed for 17 families where the proband was also noted to have depression (with an SDS index value > or =60). We found that the presence of depression did not influence the observed results (p = 0.22).
CONCLUSION: Our study of 40 multicase families confirms existence of a possible gene for FM that is linked with the HLA region. Our results should be regarded as preliminary and their independent confirmation by other studies is warranted.