Final answer:
Trisomy 16 is the most common chromosomal aneuploidy in abortuses, marked by an extra chromosome 16 in the cells.
Step-by-step explanation:
The most common chromosomal aneuploidy in abortuses is Trisomy 16, which is characterized by the presence of an extra chromosome 16, leading to a total of 47 chromosomes in the cells.
An individual with a normal chromosome number is described as euploid, which for humans means 22 pairs of autosomes and one pair of sex chromosomes. Aneuploidy refers to an abnormal number of chromosomes, including conditions such as monosomy and trisomy. While most aneuploid pregnancies result in spontaneous miscarriage, some aneuploidies such as Trisomy 13, 15, 18, 21, and 22 can lead to offspring that survive for a period of time post-birth. However, Trisomy 16 is particularly noteworthy for being prevalent among spontaneous miscarriages. Although Down syndrome, which is caused by an extra copy of chromosome 21, is the most recognized trisomy in live births, Trisomy 16 stands out as the most common cause of pregnancy loss due to chromosomal aneuploidy.
The most common chromosomal aneuploidy in abortuses is Trisomy 21, also known as Down syndrome. Trisomy 21 is caused by the nondisjunction of chromosome 21, resulting in the presence of an extra complete chromosome 21 or part of it. Unlike other trisomies, Down syndrome is the only autosomal trisomy where affected individuals can survive to adulthood.