Down's syndrome is associated with which type of genetic mutation?

Down's syndrome, also known as trisomy 21, is primarily associated with a chromosomal mutation. This condition occurs when an individual has three copies of chromosome 21 instead of the usual two. This extra chromosome arises from a nondisjunction event during cell division, where chromosomes fail to separate properly. The resulting genetic imbalance leads to the characteristic features and developmental challenges associated with Down's syndrome.

Understanding the nature of the mutation is crucial in medical genetics. Chromosomal mutations, such as the extra chromosome in Down's syndrome, can have significant phenotypic consequences for an individual compared to other types of mutations. For example, autosomal recessive mutations typically require two copies of a mutated gene for the phenotype to manifest, while sex-linked mutations are located on sex chromosomes and tend to follow different inheritance patterns. Mitochondrial mutations affect genes contained within mitochondria and usually result in inherited metabolic disorders, distinct from the chromosomal abnormalities seen in conditions like Down's syndrome.