For many with the disease and their families, these symptoms are among the most distressing aspects of the disease, often affecting daily functioning and constituting reason for institutionalization. Early behavioral changes in HD result in an increased risk of suicide. Often, individuals have reduced awareness of chorea, cognitive, and emotional impairments.Mutant huntingtin is expressed throughout the body and associated with abnormalities in peripheral tissues that are directly caused by such expression outside the brain. These abnormalities include muscle atrophy, cardiac failure, impaired glucose tolerance, weight loss, osteoporosis, and testicular atrophy. Genetics
Everyone has two copies of the huntingtin gene (HTT), which codes for the huntingtin protein (Htt). HTT is also called the HD gene, and the IT15 gene, (interesting transcript 15). Part of this gene is a repeated section called a trinucleotide repeat expansion – a short repeat, which varies in length between individuals, and may change length between generations. If the repeat is present in a healthy gene, a dynamic mutation may increase the repeat count and result in a defective gene. When the length of this repeated section reaches a certain threshold, it produces an altered form of the protein, called mutant huntingtin protein (mHtt). The differing functions of these proteins are the cause of pathological changes, which in turn cause the disease symptoms. The Huntingtons disease mutation is genetically dominant and almost fully penetrant; mutation of either of a persons HTT alleles causes the disease.
Mannosidosis is a deficiency in mannosidase, an enzyme.There are two types:

Alpha-mannosidosis
Beta-mannosidosis

See also
Swainsonine


== References ==