Table 3 clinical features of probands
| Â | Family A(III:4) | Family B(II:1) |
|---|---|---|
SEX | M | M |
Age(year) | 4 | 29 |
Age at onset(year) | 0 | 1 |
Nystagmus direction | Horizontally | Horizontally |
Best corrected visual acuity at presentation(L/R) | 0.3/0.3 | 0.3/0.2 |
Nystagmus features | no obvious fast or slow phase | no obvious fast or slow phase |
strabismus | N | External strabismus |
photophobia | N | N |
color blindness | N | N |
Night blindness | N | N |
Astigmatism | N | N |
Compensatory head position | Y | Y |
Increased nystagmus when gazing | Y | Y |
Reduced nystagmus when closing eyes | N | No autonomous feeling |
albinism | N | N |