Figure 3: The proportion of phenotypes detected in WS types 1, 2, and 4. Dystopia canthorum was the most frequent sign in WS type 1 (100%, 27/27), followed by sensorineural hearing loss (88.9%, 24/27), heterochromia iridis (81.5%, 22/27), hair hypopigmentation (14.8%, 4/27), constipation (1/27, 3.7%), and pigmentation spots (1/27, 3.7%). In WS type 2, sensorineural deafness (94.7%, 54/57) and heterochromia iridis (87.7%, 50/57) were still the most common clinical signs and symptoms, followed by freckles (31.6%, 18/57), hair hypopigmentation (24.6%, 14/57), hypopigmented skin lesions (5.3%, 3/57), and congenital ptosis (3.5%, 2/57). Amblyopia (1.8%, 1/57), congenital ptosis (1.8%, 1/57), and narrow palpebral fissures (1.8%, 1/57) are rare and unique symptoms in WS type 2 in the Chinese population.