We present three cases of trisomy 9 mosaicism diagnosed by amniocentesis with ongoing pregnancies after referral to our center due to fetal abnormalities. Two cases were associated with severe fetal growth restriction (FGR), each of which resulted in an intrauterine fetal demise (IUFD) in the third trimester. The other case involved mild FGR with a congenital diaphragmatic hernia and resulted i...

Trisomy 9 is a rare chromosomal abnormality with a very poor prognosis depending mostly on the amount and exact location of the duplicated genetic material. Most of the fetuses with complete trisomy 9 are spontaneously aborted in the early first trimester and therefore it is uncommonly seen at the time of 11-14 weeks’ scan. The diagnosis is usually made after fetal karyotyping performed for rou...

We report a case of fetal nuchal cystic hygroma associated with aortic coarctation and trisomy 21. A stillborn baby, delivered at 15 weeks and 5 days of gestation, had a huge nuchal cystic hygroma. Autopsy revealed aortic coarctation of the periductal type with patent ductus arteriosus, endocardial cushion defect and left ventricular hypoplasia. Trisomy 21 was evident by karyotyping. Macroscopi...

Despite the clinical importance of trisomy 21, we have been ignorant of the causes of meiotic nondisjunction of chromosome 21. Recently, however, genetic mapping studies of trisomy 21 families have led to the identification of the first molecular correlate of human nondisjunction; i.e. altered levels and positioning of meiotic recombinational events. Specifically, increases in 0 exchange events...

Of 1,036 children with newly diagnosed non-T, non-B acute lymphoblastic leukemia (ALL) and a demonstrated cytogenetic abnormality treated on the frontline Pediatric Oncology Group (POG) therapeutic trial 8602, there were 33 patients with trisomy 21 as the sole abnormality. Of these 33 ,14 had Down syndrome (DS). Although the nonDS (NDS) trisomy 21 cases tended to be older than the DS cases, the...

A 1-year-old girl with partial 5q trisomy and partial 7q monosomy had ocular abnormalities that included bilateral blepharoptosis and Leber's congenital amaurosis. A single bright-flash electroretinogram (dark-adapted, white stimulation) disclosed subnormal bilateral responses. Her maculas showed a reddish spot surrounded by a broad, greyish retinal zone. Cytogenetic studies disclosed deletion ...

The management of twin pregnancies discordant for trisomy 21 is dependent on the gestation at diagnosis, chorionicity, and parental preference. Our experience with the management of 15 cases in 1,839 twin pregnancies over a 12-year period is described. Selective termination is not always associated with a successful outcome for the normal co-twin. Two of the three monochorionic twin pregnancies...