What evidence indicates that humans with aneuploid karyotypes occur at conception but are usually inviable?

Key Concepts

Aneuploidy

Aneuploidy refers to the presence of an abnormal number of chromosomes in a cell. In humans, this condition can arise from errors during meiosis, leading to gametes with extra or missing chromosomes. Common examples include Down syndrome (trisomy 21) and Turner syndrome (monosomy X). While aneuploidy can occur at conception, many aneuploid embryos fail to develop properly.

Karyotype

A karyotype is a visual representation of an individual's complete set of chromosomes, organized by size and shape. It is used to identify chromosomal abnormalities, such as aneuploidy. Karyotyping can reveal the number of chromosomes and any structural changes, providing crucial information about genetic disorders and their potential viability.

Embryonic Viability

Embryonic viability refers to the ability of an embryo to develop into a healthy fetus and ultimately a live birth. Many aneuploid embryos are inviable due to the severe genetic imbalances they present, which disrupt normal development. Research indicates that a significant proportion of conceptions with aneuploid karyotypes result in early pregnancy loss, highlighting the critical role of chromosomal integrity in successful gestation.