Final answer:
FHIT on chromosome 3 is associated with Huntington's disease, a progressive nervous system disorder caused by a dominant allele.
Step-by-step explanation:
The gene FHIT located on chromosome 3 in humans has been shown to be associated with a significant human malady. When considering genetic disorders that could match this description, one notable genetic disease is Huntington's disease, which progressively affects the nervous system. This genetic disorder is caused by a dominant allele with abnormal repetitions of the amino acid glutamine, leading to the production of a toxic protein that damages neural tissue. People who are heterozygous for the Huntington allele will inevitably develop the disease, typically after childbearing years, which means they may pass the allele to their offspring, with each child having a 50% chance of inheritance.