Rare chromosome 20 variants encountered during prenatal diagnosis

A case with an uncommon heteromorphism in the centromeric region of chromosome 20, var (20) (cen, CBG 50), and a family with a pericentric inversion of chromosome 20, inv (20) (p11.23qll.21), are reported, both detected in amniotic fluid cell cultures. It appears that small pericentric inversions of chromosome 20 have a low risk of recombination.