title: Non-disjunction of an unusual X chromosome.
abstract: Because of multiple abnormalities in her children, a young mother was investigated and shown to have a 47,XXX chromosome constitution. Additional C group chromosomes without visible centromeric constrictions were found in a number of cells from the peripheral blood, and using C and Q banding techniques these chromosomes were identified as X chromosomes. Analysis of the banding karyotypes of 300 cells revealed that the acentric X chromosomes had the ability to replicate and that this replication was associated with non-disjunction leading to aneuploid cells. Even though cultured skin cells did not have acentric or extra chromosomes in addition to the triple-X, examination of buccal mucosa cells for the presence of X-bodies suggested that the phenomenon of non-disjunction was present in the epithelial cells of the patient. In addition to the X without a visible centromeric constriction, either acentric D or E chromosomes were found. The data suggest that a functional defect in the cells per se is responsible for the appearance of the acentric chromosomes.
mesh_terms: D000328:Adult; D001399:Azure Stains; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000648:ultrastructure; D002906:Chromosomes, Human, 6-12 and X; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D010375:Pedigree; D011796:Quinacrine; D012728:Sex Chromatin; D012730:Sex Chromosomes; D012867:Skin / Q000166:cytology
chemical_list: D001399:Azure Stains; D011796:Quinacrine