Any megalencephaly-polymicrogyria-postaxial polydactyly-hydrocephalus syndrome in which the cause of the disease is a mutation in the CCND2 gene. The disease is megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome 3 (Monarch Disease Ontology identifier MONDO_0014408). Also known as: CCND2 megalencephaly-polymicrogyria-postaxial polydactyly-hydrocephalus syndrome, megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome type 3, megalencephaly-polymicrogyria-postaxial polydactyly-hydrocephalus syndrome caused by mutation in CCND2.