[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.
Sèle
B
B
Laboratoire de Cytogénétique et Biologie de la Reproduction, Faculté de Médecine de Grenoble, La Tronche, France.
Pellestor
F
F
Rousseaux
S
S
Raymond
L
L
Cozzi
J
J
Pelletier
R
R
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.