Monozygotic twins with discordant karyotypes are extremely rare and usually involve the sex chromosomes. Discordance for autosomal aneuploidy has been reported for chromosomes 13 and 21. Few reports ...

Screening for aneuploid pregnancies is routinely performed after 15 weeks of gestation and has a sensitivity of approximately 65 percent, with a false positive rate of 5 percent. First-trimester ...

During the year 1966, 7 infants with the D-trisomy syndrome presented at Los Angeles County General Hospital and thus afforded the opportunity to investigate the hemoglobin characteristics in a rather ...

An academic who became pregnant with her second child, aged 44, has shown that abnormal cells in the early embryo are not necessarily a sign that a baby will be born with a birth defect such as Down’s ...

Changes in either chromosome structure or number can occur during cell division. Each human has 46 chromosomes, 22 pairs of autosomes and 1 pair of sex chromosomes (XX: female or XY: male). During ...