The 18ph+ chromosome heteromorphism

Letter to the Editor. Yet Another Variation on the Theme of Chromosome 18 Hetermorphisms?

“…There have been several reports in the literature concerning heteromorphisms of the pericentromeric region of chromosome 18, most of which involved dark staining heterochromatin localized to the short arm region but none of them were accompanied by phenotypic anomalies (Pittalis et al, 1994a,b;Zelante et al, 1994;Sensi et al, 1994). Complete duplication of the whole short arm of chromosome 18 has also been reported, also without associated phenotypic abnormalities (Wolff et al, 1991).…”