We observed in the DDD dataset11 two individuals (P1, DDD: 304967 and P2, DDD: 303133) with identical de novo mutations (DNMs) in the tumor suppressor gene MAX, resulting in an arginine (Arg)-to-glutamine (Gln) substitution at residue 60 (c.179G>A [GenBank: NM_002382.5] [p.Arg60Gln]) and overlapping phenotypes of polydactyly and macrocephaly, a rare combination in DDD observed in 18/13,610 (0.132%) participants. This evidence concerns the gene MAX and Macrocephaly.