Paternal gonadal mosaicism detected in a couple with recurrent abortions undergoing PGD: FISH analysis of sperm nuclei proves valuable.
Many couples are now seeking preimplantation genetic diagnosis (PGD) and fluorescence in-situ hybridization (FISH) as an alternative approach to avoid spontaneous abortion by ensuring transfer of presumed chromosomally normal embryos. This case report describes unexpected findings in a couple having three spontaneous abortions and two failed IVF cycles. In two IVF PGD cycles, four of 13 (30.8%) embryos (blastomeres) demonstrated duplication involving the Down syndrome critical region, detectable by a locus specific chromosome 21 probe. The same duplication was subsequently detected by FISH in 66 of 1002 (6.6%) sperm nuclei, demonstrating paternal gonadal mosaicism. Cytogenetic studies of peripheral blood revealed normal karyotypes in both the male and female partners. This identification of paternal germ cell or gonadal mosaicism suggests that analysis of sperm nuclei prior to undergoing IVF with PGD may be of value in patients with recurrent spontaneous abortions or multiple failed IVF.
Somprasit
Charintip
C
Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, Texas 77030, USA.
Aguinaga
Monica
M
Cisneros
Pauline L
PL
Torsky
Sergey
S
Carson
Sandra A
SA
Buster
John E
JE
Amato
Paula
P
McAdoo
Sallie Lou
SL
Simpson
Joe Leigh
JL
Bischoff
Farideh Z
FZ
D000026:Abortion, Habitual / Q000235:genetics*; D000328:Adult; D001755:Blastocyst / Q000378:metabolism; D002467:Cell Nucleus / Q000648:ultrastructure*; D004314:Down Syndrome / Q000175:diagnosis / Q000235:genetics; D004624:Embryo Transfer; D005220:Fathers; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro / Q000379:methods; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008297:Male; D009030:Mosaicism; D019836:Preimplantation Diagnosis / Q000379:methods*; D013094:Spermatozoa / Q000648:ultrastructure*