Age of Onset
Age of onset varies, and we’ve observed that the longer it takes to arrive at diagnosis, the later the patents recall the onset of symptoms. Typical age of onset is between the ages of 2 and 4. Subjects present with generalized low muscle tone, resulting in collapsed arches. They have no reflex response from the knee down. They have sensory ataxia (loss of sensory input into the control of movement), and trouble balancing. For example, they cannot pull a shirt over their heads without leaning against something.