Presenting Symptoms
For a majority of the subjects in this study, the first symptom
identified was nystagmus (11 of 16, 68.8%). In most cases, nystagmus
was an isolated symptom but 3 of the 11 cases (27.3%) each had one
additional symptom. These included seizures, “couldn’t lift legs,” and
head lag in a baby that also had cleft lip and palate. In the remaining
subjects, the presenting symptoms included “missed developmental
milestones”, “could not sit up”, “head lag”, “lower extremity
tremors”, and “strabismus”. The average age at which the presenting
symptom was noticed was 3.1 months (range from birth to 12 months; SD=
3.4 months).