Common Features/Symptoms
Ninety-four percent (15/16) of the subjects were reported to have had
nystagmus at some point in their life. The average age at which
nystagmus was noticed was 2.3 months (range from birth to 9 months,
SD=2.5, n=12 subjects for whom age of onset was available).
All subjects reportedly had hypotonia (15 of 15). For most, the age of
onset was between birth to 12 months (9/10 responses). For one
individual, the onset of hypotonia occurred after a car accident when
the individual was in his 30s.
Sixty-three percent (10/16) of subjects had feeding problems. For the 5
subjects for which the age of onset was reported, it varied from less
than 1 year of age to 31 years of age.
Forty percent (6 of 15) of subjects had gastroesophageal reflux. Age of
onset was reported for 5 subjects and ranged from birth to 15 years of
age (average age 6). All subjects reported to have gastroesophageal
reflux were also reported to have feeding problems; however, not all
subjects who had feeding problems also had reflux.