[Chromosome abnormalities of human gametes].
Human newborns carrying chromosomal abnormalities are the survivors of a considerably larger cohort of affected conceptions. A direct cytogenetic study of these conceptuses would imply their destruction. Moreover, the ability to determine the parental origin of an additional or missing chromosome is limited from a methodological point of view. The cytogenetic study of human gametes provides information on these mechanisms. Several large-scale studies on sperm complements of normal men give an estimated abnormality rate of 10%. Our results concerning four carriers of reciprocal translocations show no evidence for a selection against abnormal sperm. Since about 30% of the recovered eggs fail to become fertilized in IVF programs, human oocytes have become available for large cytogenetic studies. Analysis of oocytes II provides information on the first meiotic non-disjunction rate. In our sample of 405 karyotypes, the rate of aneuploidy was 27%. No relationship was established between this frequency and the mode of stimulation of ovulation. No increase was observed with maternal aging.
Laboratoire de Cytogénétique et Biologie de la Reproduction, Faculté de Médecine de Grenoble, La Tronche, France.
B
B
Sèle
F
F
Pellestor
S
S
Rousseaux
L
L
Raymond
J
J
Cozzi
R
R
Pelletier
D000328:Adult; D000782:Aneuploidy; D002869:Chromosome Aberrations / Q000209:etiology / Q000235:genetics; D025063:Chromosome Disorders; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008423:Maternal Age; D008540:Meiosis; D009630:Nondisjunction, Genetic; D010062:Ovulation Induction; D010063:Ovum; D011247:Pregnancy; D013094:Spermatozoa / Q000002:abnormalities*; D014178:Translocation, Genetic
Anomalies chromosomiques dans les gamètes humains.