Novel mutations in the COL2A1 gene in Japanese patients with Stickler syndrome

Stickler syndrome is an inherited connective tissue disorder that affects the eyes, cartilage and articular tissues. The phenotypes of Stickler syndrome include congenital high myopia, retinal detachment, premature joint degeneration, hearing impairment and craniofacial anomalies, such as cleft palate and midline facial hypoplasia. The disease is genetically heterogeneous, and the majority of the cases are caused by mutations in the COL2A1 gene. We examined 40 Japanese patients with Stickler syndrome from 23 families to determine whether they had mutations in the COL2A1 gene. This analysis was conducted by examining each patient's genomic DNA by Sanger sequencing. Five nonsense, 4 splicing and 8 deletion mutations in the COL2A1 gene were identified, accounting for 21 of the 23 families. Different mutations of the COL2A1 gene were associated with similar phenotypes but with different degrees of expressivity.