Chromosomal variants and nondisjunction

Abstract

Additions to the long arm and pericentric inversions of human chromosome 9 may be associated with reduced sperm counts, subfertility and recurrent spontaneous abortions. Mitosis in cells with and without chromosome 9 variants were studied in peripheral blood lymphocyte cultures, and significantly increased numbers of hyperdiploid cells were found in variant cells. These variants may cause or increase the likelihood of mitotic nondisjunction. The rate of mitotic nondisjunction reported (4%) is low enough that it may not explain reproductive failure.