Chromosome 20

Abstract

Reports of variants of the centromeric region of chromosome 20 are rare. Only one case with 20ph+ is reported in a couple with recurrent miscarriages (Romain et al., J Med Genet 28:477–478, 1991). A second case was submitted to us as a normal variant (Fig. 25.1b), and a third case was detected in a patient with infertility (Wyandt, Atlas of human chromosome heteromorphisms, 2004). In the latter case, the 20ph+ was positive by G- and C-banding and by FISH with alpha satellite probe D20Z1. In addition to 20ph+, pericentric inversion in 20h also appears to be rare, there being one reported prenatal case known to us (Petersen, Prenatal Diagn 6:363–367, 1990). Further reports on variants of the centromeric region of chromosome 20 are needed to know their significance.