Delayed psychomotor development |
Variable degree of mental retardation (very frequent sign) |
Alopecia (very frequent sign), spare/absent scalp and eyebrow hair (frequent sign), dysarthria |
Dysmorphic features: high forehead, flat occiput, triangular face, prominent nasal root, hypertelorism, and down-slanting palpebral fissures. |
Hyper/hypogonadotrophic hypogonadism and late puberty (very frequent sign) |
Sensorineural deafness (very frequent sign) |
Electrocardiographic abnormalities and insulin dependent diabetes mellitus (very frequent signs) |
No ocular manifestations |