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
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.
Yunus MB, Khan MA, Rawlings KK, Green JR, Olson JM, Shah S