Huntington's disease

Hereditary Huntington’s disease

People with HD also develop impaired coordination, slurred speech, and difficulty feeding and swallowing. HD typically begins between ages 30 and 50. An earlier onset form called juvenile HD occurs under age 20.  Its symptoms differ somewhat from adult onset HD and include rigidity, slowness, difficulty at school, rapid involuntary muscle jerks called myoclonus, and seizures.