Abstract
Purpose :
This study aims to reveal the clinical and genetic characteristics of COL2A1-associated Stickler syndrome in Chinese children.
Methods :
The 32 unrelated probands with heterozygous COL2A1 variants detected from in-house exome sequencing data, were recruited in this study in the last five years. Furthermore, the variants underwent multi-step in-silico tools prediction, comparison analysis of databases, Sanger sequencing confirmation, and co-segregation analysis. The clinical data were gathered and analyzed.
Results :
Of the 32 unrelated Chinese pedigrees, 30 potential pathogenic COL2A1 variants were identified. These patients had a mean age at the first visit of 5.78±8.31 years. The mean axial length and refraction for the right eye were -9.39 ± 4.75 diopters and 25.9 ± 1.7 mm, respectively, while for the left eye, they were -9.2 ± 4.5 diopters and 26.3 ± 2.1 mm. The vitreous opacity was observed in 12 probands. The available OCT scans showed normal foveal morphology (81%) to Grade 1 foveal hypoplasia (14.3%) in most probands. The majority of the probands exhibited the classic myopic fundus, with 58% classified as Category 1 (tessellated fundus) and 25.8% classified as Category 2 (chorioretinal atrophy). Except for three probands diagnosed with Stickler syndrome, the referring diagnosis of probands during their first visit was predominantly simple high myopia (65.6%). The specific peripheral retinal changes were observed in 47.8% of probands. The extraocular symptoms were only identified in six probands including skeletal and facial abnormalities, auditory dysfunction, or cleft palate. Among 20 probands with a family history of high myopia or retinal detachment, the genetic defects were identified in 65% of parents with high myopia.
Conclusions :
This study suggests that the posterior pole of the fundus and extra-ocular manifestations observed in children with Stickler syndrome were not as obvious or distinctive as those found in adults. Thus, the peripheral retina examination, as well as genetic testing and counseling, is recommended for children with high myopia to identify signs of risk factors for retinal detachment.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.