Sperm chromosome analysis of an infertile patient with a 95% mosaic r(21) karyotype and normal phenotype.
OBJECTIVE
To examine sperm meiotic segregation in a man with mosaic ring chromosome 21.


METHODS
Case report.


METHODS
Hospital departments of reproductive biology, cytogenetics, gynecology, and obstetrics.


METHODS
One patient referred for cryptozoospermia, heterozygous for a ring chromosome.


METHODS
Fluorescence in situ hybridization with chromosome 21-specific probes after sperm selection.


RESULTS
A total of 169 spermatozoa were selected; 92.3% carried a normal 21 chromosome, 6.5% the ring chromosome, and 1.2% both.


CONCLUSIONS
Ring chromosome frequency in mature sperm cells was low and may be due to preferential meiosis of normal spermatogonia,which could explain the cryptozoospermia and unexpected ratio in this case.
Hammoud
Ibrahim
I
Department of Reproductive Biology, Centre Hospitalier Intercommunal de Poissy, Poissy, France.
Gomes
Denise Molina
DM
Bergere
Marianne
M
Wainer
Robert
R
Selva
Jacqueline
J
Vialard
François
F
D020090:Chromosome Segregation; D002891:Chromosomes, Human, Pair 21; D004314:Down Syndrome / Q000235:genetics; D005838:Genotype; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007248:Infertility, Male / Q000235:genetics* / Q000503:physiopathology; D007621:Karyotyping; D008297:Male; D008540:Meiosis / Q000235:genetics; D009030:Mosaicism; D010641:Phenotype; D027724:Reproductive Techniques, Assisted; D012303:Ring Chromosomes; D018570:Risk Assessment; D055101:Semen Analysis; D013076:Sperm Count; D013081:Sperm Motility; D013091:Spermatogenesis / Q000235:genetics*