Objective: To identify chromosomal regions containing genes involved in the susceptibility to primary Raynaud's phenomenon (RP).
Methods: Six extended families with multiple individuals affected with primary RP (n = 37) were examined for linkage in a 2-stage, whole-genome screen, using a total of 298 microsatellite markers.
Results: Multipoint, nonparametric linkage analysis identified 5 areas of possible linkage, with a nominal level of significance of P < or = 0.05. Analysis of a finer map of markers in these regions defined the regions of linkage as 21.4 cM on 6q13-6q23.3 (D6S261; P = 0.0004), 10.2 cM on 7p22-7p15 (D7S664; P = 0.014), 1.6 cM on 9p23-9p22 (D9S156; P = 0.0075), 5.1 cM on 17p13.1-17p12 (D17S1791; P = 0.036), and 11.8 cM on Xp11.4-Xp11.23 (DXS8054; P = 0.006). Three potential candidate genes map to these regions: the beta subunit of the muscle acetylcholine receptor and the serotonin 1B and 1E receptors.
Conclusion: These results provide evidence of the presence and location of genes that are involved in the genetic susceptibility to primary RP.