A Region of Chromosome 20 Is Linked to Leprosy Susceptibility in a South Indian Population

A major susceptibility locus for leprosy has recently been mapped on chromosome 10 (10 p 13 ) by genome-wide linkage analysis. Microsatellite markers from this genome screen that showed suggestive evidence of linkage to leprosy were evaluated in an additional 140 families with affected sib pairs. A second region of linkage has thus been identified on chromosome 20 (20 p 12). The peak of linkage lies at marker D20S115 which has a significant single-point maximum logarithm of odds score of 3.48 (P=.00003). Transmission disequilibrium testing of the microsatellite markers in 20 p 12 showed that the marker D20S835 is associated with protection against leprosy (P=.021), which suggests that a locus controlling susceptibility lies close to this marker.