Retinal detachment in Type IX collagen recessive Stickler syndrome

Area of Science:

• Genetics
• Ophthalmology
• Rheumatology

Background:

• Stickler Syndrome (SS) encompasses diverse inherited disorders characterized by ocular, joint, and orofacial abnormalities.
• Dominant SS, often linked to COL2A1/COL11A1 variants, carries a significant risk of retinal detachment (RD).
• Recessive SS, associated with type-IX collagen gene variants (COL9A1, COL9A2, COL9A3), is less understood, particularly regarding RD risk and patient phenotypes.

Purpose of the Study:

• To investigate the incidence of RD in patients with type-IX recessive Stickler Syndrome.
• To evaluate the potential benefit of prophylactic retinopexy in this patient group.
• To characterize the clinical phenotypes associated with recessive SS for earlier diagnosis.

Main Methods:

• A cohort of 13 patients from 11 families with type-IX recessive SS was identified.
• Patients received multidisciplinary assessments including ophthalmology, rheumatology, and audiology.
• Genetic variants and clinical manifestations were analyzed.

Main Results:

• Six families presented novel genetic variants; seven families had consanguineous parents.
• Retinal detachment (RD) occurred in 15.4% of patients, primarily from horseshoe tears; no giant retinal tears (GRTs) were observed.
• High myopia and abnormal vitreous architecture were common; hearing loss (91.7%) was more prevalent than in dominant SS. Orofacial features like cleft palate were absent, but midfacial hypoplasia occurred in 30.8%.

Conclusions:

• The incidence of RD and GRTs appears lower in recessive SS compared to dominant forms, though sample size is limited.
• Prophylactic retinopexy is not routinely indicated for recessive SS.
• Case-by-case consideration for fellow eyes of patients with unilateral GRT detachment is advised.