Autosomal mosaicism in amniotic fluid cells from a twin pregnancy

Abstract

Amniocentesis was performed on a 39-year-old gravida 4 woman because of maternal age. Ultrasonography demonstrated a twin pregnancy, and two amniotic fluid specimens were obtained under direct ultrasound guidance. All cells analyzed from the first specimen were 46,XX. In the second specimen, one colony in each of two flasks had trisomy 9; the remaining 3 colonies analyzed were 46,XX. The total cell count in the second specimen was 14 (24%) of 58 cells which were trisomic for chromosome 9. The parents elected to continue the pregnancy, which resulted in two live-born infants, a male and a female, both chromosomally normal. The most likely explanation for the amniotic fluid finding is that fluid from one sac was sampled twice and that trisomic cells from the amnion were obtained during the second tap.

Prenatal diagnosis of mosaic trisomy 9

“…Although prenatal diagnosis of trisomy 9 mosaicism has been reported the majority of cases have not been confirmed by the fetal studies. In the case reported by Greenberg et al (1982), the mosaicism for trisomy 9 was not confirmed post-natally and may have been pseudomosaicism. The report of prenatal diagnosis of trisomy 9 mosaicism by Pfeiffer et al (1984) was not confirmed from fetal tissue but rather, limited to fetal membranes only.…”

“…Trisomy 9 was first described by Feingold and Atkins (1973) and was further delineated into a well-defined syndrome by Sutherland et al (1976). The prenatal diagnosis of trisomy 9 has been previously reported (Francke and Benrirschke, 1975;Greenberg et al, 1982., Pfeiffer et al, 1984Hsu and Perlis, 1984).…”

Prenatal detection of trisomy 9 mosaicism

“…Of the 234 mosaic cases reported in these collaborative studies, six (2.6 per cent) demonstrated trisomy 9 mosaicism (Hsu and Perlis, 1984). Additionally, there have been a few other cases of either complete or mosaic trisomy 9 detected prenatally (Table 3) (Francke et al, 1975;Frohlich, 1982;Greenberg et al, 1982;Purvis-Smith et al, 1983;Zadeh et al, 1987).…”

Prenatal diagnosis of trisomy 9 mosaicism: Two new cases

“…Mosaic trisomy 9 was first described in 1973(Haslam et al, 1973. Prenatal diagnosis of this condition has been previously reported by others (Purvis-Smith et al, 1983;Pfeiffer et al, 1984;Hsu and Perlis, 1984;Zadeh et al, 1987;Schwartz et al, 1989;Sherer et al, 1992).…”