Partial duplication 2p as the sole abnormality in two cases with anencephaly.

Anencephaly/NTD has been observed in aneuploid and non-aneuploid individuals. We present two cases of anencephaly diagnosed prenatally with partial duplication of the short arm of chromosome 2 as the sole abnormality. The absence of aneuploidy involving other regions of the genome in these cases, further substantiates suggestions of the existence of a gene or genes on the short arm of chromosome 2 critical in the development of the central nervous system.