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).