The primary erythermalgia-susceptibility gene is located on chromosome 2q31-32

Primary erythermalgia is a rare disorder characterized by recurrent attacks of red, warm, and painful hands and/or feet. The symptoms are generally re fractory to treatment and persist throughout life. Five kindreds with multi ple cases of primary erythermalgia were identified, and the largest was sub jected to a genomewide search. We detected strong evidence for linkage of t he primary erythermalgia locus to markers from chromosome 2q. The highest L OD score (Z) was obtained with D2S2330 (Z(max) = 6.51). Analysis of recombi nation events identified D2S2370 and D2S1776 as flanking markers, on chromo some 2q31-32. This defines a critical interval of 7.94 cM that harbors the primary erythermalgia gene. Affected members within the additional families also shared a common haplotype on chromosome 2q31-32, supporting our linka ge results. Identification of the primary erythermalgia gene will allow a b etter clinical classification of this pleomorphic group of disorders.