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...

down's syndrome (ds) is the most common chromosomal abnormality in human. subjects with ds are known to be peridisposed to develop leukemia. the molecular basis of the association between ds and leukemia is unknown. the unscheduled dna synthesis (uds) test measure the ability of dna-repair in mammalian cells after excision of a stretch of dna containing the region of damage induced by chem...

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...

The results of chromosome analyses on 500 cases of perinatal deaths are reported. It was found that 4.8% were chromosomally abnormal, but 90% of the chromosomally abnormal were either clinically malformed or macerated fetuses. Of the macerated fetuses, 9% were chromosomally abnormal and of these 33% had trisomy 21. The data suggest that the high loss of trisomy 21 fetuses in later stages of pre...

While trisomy 21 is a common genetic disorder in singletons, the incidence among identical twins is very rare, occurring in approximately 1-2 per 1000 twin gestations. Trisomy 21 is associated with high incidence of congenital heart defects, and commonly occurs with ventricular septal defects (VSDs). Physiologic burden of VSDs depends on prevalence of anatomic and other circulatory factors. A c...

OBJECTIVE To examine whether in pregnancies with fetal trisomy 21 the level of maternal serum free beta-human chorionic gonadotropin (beta-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11 + 0 to 13 + 6 weeks' gestation is independent of the presence or absence of tricuspid regurgitation and to estimate the performance of a screening test that combines tricuspid regurgitation with f...

Techniques have been reported in which fluorescence in situ hybridisation (FISH) and cosmid probes are used to detect trisomy 21 (and other abnormalities involving chromosomes X, Y, 13, and 18) on uncultured amniocytes. However the detection rate of trisomy 21 is lower than for the other anomalies owing to a larger number of uninformative results and false negatives. We report the simultaneous ...

Down syndrome or trisomy 21 is the most common cause of prenatal chromosome abnormalities with approximately 50% of all reported chromosome conditions. With the successful introduction of noninvasive prenatal testing (NIPT) for Down syndrome into routine prenatal care, it is important to understand the risks, benefits, and limitations in order to guide patients in making an informed decision. H...

Cytogenetic analysis in 60 clinically suspected cases of Down syndrome and their parents was carried out using conventional Giemsa–trypsin-banding technique. Fifty-five individuals (91%) exhibited a free trisomy 21. Robertsonian translocations were seen in three cases and two cases exhibited a normal karyotype. A four-month-old child, the second-born of non-consanguineous parents, possessed an ...