The additional observation by Timberlake et al. that the genotype atthe rs1884302 SNP appeared strongly related to manifestation of CRS in SMAD6-positive individuals4,18 has attracted attention as a potentialexample of digenic or two-locus inheritance.36 However, our own data donot support any major modifying role for this SNP (Table 2). The gene discussed is SMAD6; the disease is congenital rubella syndrome.