Chromosome 11

Abstract

A variant of the centromeric region of chromosome 11 has been observed in at least three cases. Till et al. (Prenat Diagn 11:481–482, 1991) describe a duplication of the centromere in a fetus and a 39 year-old mother. The fetus had no obvious abnormalities. C- and G- banding suggested the variant chromosome was a pseudodicentric with inactivation of one centromere. A case with a large C-band positive, Q-band negative centromeric region of chromosome 11 (Fig. 16.1a) was observed in a man identified through fetal loss in his wife (Aiello et al., Am J Med Genet 50:294–295, 1994). The authors reported this as a familial variant whose clinical significance is unknown. A third case of a large centromeric variant (Fig. 16.1b), ascertained prenatally, that was paternal in origin, and positive for alpha satellite D11Z1, is also know to us (Wyandt, Atlas of Human Chromosome Heteromorphisms, pp. 3–10, 2004).