Huntington Disease

Huntington's disease, also called Huntington's chorea, chorea major, or HD, is a genetic neurological disorder characterized by abnormal body movements called chorea and a lack of coordination; it also affects a number of mental abilities and some aspects of behavior. The name is derived from the physician George Huntington who described the disorder in 1872. In 1993 the gene causing HD was found, making it one of the first inherited genetic disorders for which an accurate test could be performed.

Huntington's disease is autosomal dominant, needing only one affected allele from either parent to inherit the disease. Homozygous individuals, who carry two mutated genes because both parents passed on one, are rare. In families where neither parent has HD, new mutations account for truly sporadic cases of the disease. The frequency of these de novo mutations is extremely low.

Huntington's disease is one of several polyglutamine diseases caused by a trinucleotide repeat expansion. This expansion is in the Huntingtin gene, which normally codes for Huntingtin protein (Htt), producing mutant Huntingtin (mHtt). The presence of this protein increases the rate of neuron cell death in select areas of the brain, affecting certain neurological functions. The loss of neurons isn't fatal, but complications caused by symptoms reduce life expectancy. There is currently no proven cure, so symptoms are managed with a range of medications and supportive services.

Methodology: PCR, Southern Blot

Purpose: Confirmation of Clinical Diagnosis

ICD-9 Code 333.4

Test Requisition: Molecular Requisition

CPT Code: 81401 Cost: $355.00

Turn-around-time: 4 weeks