LBX1 and split hand-foot malformation: In 1995, Nunes indicated that the locus of SHFM3 was mapped to chromosome 10q24–q25.[13] In 2003, de Mollerat et al. showed that submicroscopic chromosomal duplication within the SHFM3 locus are associated with non-syndromic SHFM in familial and sporadic cases.[4] The previous findings indicated maximum duplication to be found in at least 6 genes: LBX1 (ladybird homeobox 1), BTRC (â- transducin repeat containing), POLL (polymerase (DNA directed), lambda) and a portion of DACTYLIN (FBXW4, F-box and WD repeat domain containing 4).