Hyperreflective foci (HRF) were defined as well-circumscribed and scattered dots with hyperreflective signals in optical coherence tomography (OCT). HRF can be seen in the vitreous cavity as well as the retinal and choroidal layers. Different OCT examination equipment and modes have differences in HRF detection results, and HRF counting methods gradually develop from manual counting to semi-automatic counting and automatic counting. HRF may be lens fragments, inflammatory cells, migrating photoreceptor complexes, exuded proteins or lipids, activated microglia, degenerated photoreceptor cells, migrating retinal pigment epithelial cells, and degraded lipofuscin deposits. The number and distribution of HRF are associated with the progression and the prognosis of a variety of ocular diseases, such as diabetic retinopathy, age-related macular degeneration, central serous chorioretinopathy, retinal dystrophy, etc. HRF are clinically important in guiding the personalized treatment of patients.
ObjectiveTo observe and analyze the clinical phenotype and genetic characteristics of COL2A1 and COL11A1 de novo mutation (DNM) related Stickler syndrome type I and II patients. MethodsA family-based cohort study. From December 2023 to November 2024, 4 patients (all probands) with Stickler syndrome diagnosed by clinical and genetic testing in Department of Ophthalmology of People's Hospital of Ningxia Hui Autonomous Region and their parents (8 cases) were included in the study. The patients came from 4 unrelated families. A detailed medical history was taken, and the patients underwent best-corrected visual acuity (BCVA), refraction, and fundus color photography examinations. Systemic examinations included the oral and facial regions, skeletal, joints, and hearing. Peripheral venous blood samples were collected from the patients and their parents, and genomic DNA was extracted. Whole-exome sequencing was used to screen for pathogenic genes and their loci, which were then validated by Sanger sequencing and combined with segregation analysis in the families to identify candidate gene mutation sites. The candidate variants were assessed for pathogenicity according to the American College of Medical Genetics and Genomics (ACMG) criteria and guidelines for the classification of genetic variants. Additionally, cross-species conservation analysis was performed to determine the evolutionary conservation of wild-type amino acids, and protein three-dimensional modeling techniques were used to characterize the spatial conformational changes of the variant proteins and the alterations in their local hydrogen bond networks. ResultsAmong the 4 patients, there were 2 males and 2 females; their ages ranged from 3 to 12 years. There were 2 cases of Stickler syndrome type I (proband of families 1 and 2) and 2 cases of type II (proband of families 3 and 4). The diopters ranged from －8.00 to－11.0 D. BCVA ranged from no light perception to 0.6-. There were 2 cases each of vitreous membrane-like and “bead-like” opacity. Three cases showed peripapillary atrophy arcs and leopard pattern changes in the retina; one case had bilateral retinal detachment with a large macular hole in the left eye, which had previously been treated with vitrectomy surgery. One case had bilateral sensorineural hearing loss. There were 3 cases of simple micrognathia; one case had a flat nasal bridge, short nose, midface depression, and micrognathia. Two cases had excessive elbow joint extension. The phenotypes of the parents of the 4 patients were normal. Genetic testing results revealed that the probands of families 1 and 2 carried COL2A1 gene c.85+1G>C (M1) splice site variant and c.3950_3951insA (p.M1317Ifs*48) (M2) frameshift variant, respectively; the probands of families 3 and 4 carried COL11A1 gene (NM_001854.4) c.2549 G>T (p.G850V) (M3) missense variant and c.3816+6T>C (M4) splice site variant, respectively. The parents did not carry the related gene variants. Among them, M2, M3, and M4 are newly reported DNM. According to the ACMG guidelines, they were all considered likely pathogenic. The cross-species conservation analysis results showed that the wild-type amino acid of the COL11A1 gene M3 missense variant was highly conserved across multiple different species. Protein local structure modeling analysis revealed that the COL2A1 gene M2 frameshift variant and the COL11A1 gene M3 missense variant significantly altered the tertiary structure conformation of the protein, leading to abnormal spatial arrangement and hydrogen bond network in the key functional domains ConclusionThe COL2A1 gene M1 splice site variant, M2 frameshift variant, and the COL11A1 gene M3 missense variant, M4 splice site variant are respectively the potential pathogenic genes for families 1, 2, and families 3, 4; leading to the onset of Stickler syndrome type I in families 1 and 2, and type II in families 3 and 4.
ObjectiveTo investigate and analyze the relationship between genotype and phenotype in patients with early-onset high myopia (eoHM) associated with hereditary eye diseases. MethodsA family-based study was conducted among 30 families diagnosed with eoHM at Department of Ophthalmology of People's Hospital of Ningxia Hui Autonomous Region from January 2022 to June 2023. Seven families (23.3%, 7/30), all probands, and their 14 parents were included. These seven families were unrelated. Detailed patient and family histories were collected. All participants underwent comprehensive ophthalmic examinations, including best-corrected visual acuity, color vision testing, fundus color photography, optical coherence tomography, fluorescein fundus angiography, and fundus autofluorescence imaging. Full-field electroretinography was performed in three cases. Peripheral venous blood samples were collected from patients and their parents for whole-genome DNA extraction and whole-exome sequencing. Potential pathogenic variants were identified, and their pathogenicity was analyzed and confirmed by Sanger sequencing. The pathogenicity of newly discovered gene variants was evaluated according to the guidelines of the American College of Medical Genetics and Genomics (ACMG). Literature on previously reported eoHM associated with hereditary eye diseases was reviewed to analyze the relationship between variant genes and clinical phenotypes. ResultsAmong the seven families, three exhibited X-linked inheritance, two showed autosomal recessive inheritance, and two demonstrated autosomal dominant inheritance. All the patients were male. Among the seven patients, one case each was identified with congenital stationary night blindness (CSNB), Bornholm eye disease, X-linked retinitis pigmentosa (RP), cone-rod dystrophy, Knobloch syndrome, familial exudative vitreoretinopathy (FEVR), and Stickler syndrome. Genetic testing revealed nine gene variants highly correlated with the observed phenotypes. The genetic testing results revealed that all patients were found to carry nine gene variants highly associated with the phenotype, including: a hemizygous missense variant NYX c.647A>T (p.N216I) (M1), an OPN1LW LIAVA haplotype variant (M2), a hemizygous frameshift variant RPGR c.3096_3097del (p.E1033RfsTer45) (M3), compound heterozygous variants TTLL5 c.1588_1589del (p.L531EfsTer24) and c.850G>C (p.D284H) (M4, M5), compound heterozygous variants COL18A1 c.2118dup (p.G707RfsTer23) and c.3523_3524del (p.L1175VfsTer72) (M6, M7), a heterozygous missense mutation FZD4 c.1499C>T (p.T500I) (M8), and a heterozygous frameshift variant COL11A2 c.966dup (p.T323HfsTer19) (M9). Among them, M2, M4, M5, M8 and M9 were newly discovered mutation sites, and M1, M3, M6 and M7 were known mutation sites. According to the classification standards and guidelines of genetic variation issued by ACMG, M2, M3, M4, M6, M7, and M9 were judged to be pathogenic variants, while M1, M5, and M8 were of unknown clinical significance. Through literature review, it was found that eoHM was more common among the clinical phenotypes of 4 types of hereditary retinal diseases, including CSNB, Stickler syndrome, FEVR and RP. ConclusioneoHM is intricately associated with inherited eye diseases and may serve as the earliest indicator of such conditions.