Final answer:
Huntington's disease is a fatal central nervous system disorder caused by a genetic code of more than 35 triplet repetitions, leading to inevitable development of the disease in individuals carrying the Huntington allele.
Step-by-step explanation:
Central Nervous System Genetic Disorder
The fatal central nervous system disorder caused by a genetic miss code of more than 35 repetitions of a particular triplet in humans is Huntington's disease. This autosomal dominant condition leads to the degeneration of the nervous system, but symptoms may not appear until around the age of 40. The mutated gene is characterized by excessive repeats of the amino acid glutamine, making the protein toxic to neural tissues. As an autosomal dominant disorder, a person carrying the Huntington allele (Hh) has a 50% chance of passing this condition on to their offspring. Unlike chromosomal disorders such as Down syndrome, which is caused by an extra copy of chromosome 21, Huntington's disease results from a mutation within a single gene.
Individuals who are heterozygous for the Huntington allele inevitably develop Huntington's disease. Genetic counseling is recommended for individuals with a family history of the disease to determine their risk factors and whether they wish to be tested for the gene. It is important to differentiate this from other genetic diseases such as cystic fibrosis, Tay-Sachs disease, and Down syndrome, which have different genetic causes and inheritance patterns.