Huntington’s disease is usually caused by genetically inherited defect to a single gene. This defect causes the hungtintin protein to be longer which then it able to accumulate abnormally in brain cell and eventually causing brain cell death. Huntington disease is autosomal dominant which means a person only needs one defective gene to develop the disease.
Hence, a parent with a defective gene could pass along the defective copy of the gene. Each child in the family, therefore, has a 50 percent chance of inheriting the gene that causes the genetic disorder.
Huntington's DISEASE 