TWIST1 and Phocomelia: We did not find any pathogenic mutations in the remaining genes screened, including all those genes not yet associated with defined human CLM syndromes (EN1, HAND2, SPRY4 and TWIST1), as well as ROR2 and WNT7A. After this study was initiated, recessive mutations of WNT7A were reported in Al-Awadi/Raas-Rothschild/Schinzel phocomelia and Fuhrmann syndromes (MIM 228930)24; however, our cohort did not include any individuals with these disorders.