What genetic condition is commonly associated with abnormal chromosome numbers?

Down's syndrome, also known as Trisomy 21, is commonly associated with abnormal chromosome numbers. Individuals with Down's syndrome have an extra copy of chromosome 21, resulting in a total of 47 chromosomes instead of the typical 46. This additional genetic material alters normal development, leading to the distinctive physical features and varying degrees of intellectual disability associated with the condition.

Turner syndrome, while also related to chromosomal abnormalities, involves a missing or incomplete X chromosome in females, leading to a total of 45 chromosomes. However, it is not as widely recognized as being associated with an extra chromosome like Down's syndrome.

Color blindness and cystic fibrosis, on the other hand, are not linked to abnormal chromosome numbers but rather to specific genetic mutations and inheritance patterns. Color blindness typically arises from mutations on the X chromosome affecting color-detecting proteins, while cystic fibrosis is caused by mutations in the CFTR gene on chromosome 7. Thus, Down's syndrome stands out in the context of abnormal chromosome numbers due to its nature of having an extra chromosome.