title: Three cases of low chiasma frequency associated with infertility in man.
abstract: Three new cases of low chiasma frequency in infertile men are described. In the first case, all cells showed abnormal diakineses; in the second, 20% of the diakineses were desynaptic, while the remaining 80% were normal; in the third, all diakineses were desynaptic and showed chromosome fragmentation. The possible mechanisms leading to asynapsis, desynapsis or precocious chiasma terminalization are discussed.
mesh_terms: D000328:Adult; D002869:Chromosome Aberrations; D006801:Humans; D007248:Infertility, Male / Q000175:diagnosis / Q000235:genetics*; D008297:Male; D008540:Meiosis; D013081:Sperm Motility; D013094:Spermatozoa / Q000648:ultrastructure*