Congenital cataracts, a prevalent cause of blindness in children, are associated with protein aggregation. γD-crystallin, essential for sustaining lens transparency, exists as a monomer and exhibits excellent structural stability. In our cohort, we identified a nonsense mutation (c.451_452insGACT, p.Y151X) in the CRYGD gene. To explore the effect of truncation mutations on the structure of γD-crystallin, we examined the Y151X and T160RfsX8 mutations, both located in the Greek key motif 4 at the cellular and protein level in this study. Both truncation mutations induced protein misfolding and resulted in the formation of insoluble aggregates when overexpressed in HLE B3 and HEK 293T cells. Moreover, heat, UV irradiation, and oxidative stress increased the proportion of aggregates of mutants in the cells. We next purified γD-crystallin to estimate its structural changes. Truncation mutations led to conformational disruption and a concomitant decrease in protein solubility. Molecular dynamics simulations further demonstrated that partial deletion of the conserved domain within the Greek key motif 4 markedly compromised the overall stability of the protein structure. Finally, co-expression of α-crystallins facilitated the proper folding of truncated mutants and mitigated protein aggregation. In summary, the structural integrity of the Greek key motif 4 in γD-crystallin is crucial for overall structural stability.

Congenital cataract is one of the leading causes of vision loss in children, and a large proportion of cases are related to genetics. In a Chinese family, we reported a new missense mutation in CRYBA2 (c.223T>C: p.Tyr75His), which can cause autosomal dominant congenital bilateral cataract. We collected blood samples from family members (mother and two sons) and extracted DNA. Through whole-exome sequencing, we discovered a novel unreported mutation. According to relevant ACMG guidelines, this mutation was determined to be a variant of unknown clinical significance. This article further expands the site information on the CRYBA2 mutations.

OBJECTIVE: To identify genetic defects in a Chinese family with congenital posterior polar cataracts and assess the pathogenicity.
METHODS: A four-generation Chinese family affected with autosomal dominant congenital cataract was recruited. Nineteen individuals took part in this study including 5 affected and 14 unaffected individuals. Sanger sequencing targeted hot-spot regions of 27 congenital cataract-causing genes for variant discovery. The pathogenicity of the variant was evaluated by the guidelines of American College of Medical Genetics and InterVar software. Confocal microscopy was applied to detect the subcellular localization of fluorescence-labeled ephrin type-A receptor 2 (EPHA2). Co-immunoprecipitation assay was implemented to estimate the interaction between EphA2 and other lens membrane proteins. The mRNA and protein expression were analyzed by reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting assay, respectively. The cell migration was analyzed by wound healing assay. Zebrafish model was generated by ectopic expression of human EPHA2/p.R957P mutant to demonstrate whether the mutant could cause lens opacity in vivo.
RESULTS: A novel missense and pathogenic variant c.2870G>C was identified in the sterile alpha motif (SAM) domain of EPHA2. Functional studies demonstrated the variant\'s impact: reduced EPHA2 protein expression, altered subcellular localization, and disrupted interactions with other lens membrane proteins. This mutant notably enhanced human lens epithelial cell migration, and induced a central cloudy region and roughness in zebrafish lenses with ectopic expression of human EPHA2/p.R957P mutant under differential interference contrast (DIC) optics.
CONCLUSIONS: Novel pathogenic c.2870G>C variant of EPHA2 in a Chinese congenital cataract family contributes to disease pathogenesis.

BACKGROUND: Congenital cataracts, which can arise due to a combination of factors like environmental influences and genetic predisposition, significantly impact children\'s visual health globally. The occurrence rate of congenital cataracts varies from 0. 63 to 9.74 per 10,000 births. There are 7.4 instances per 10,000 children, with the highest occurrence seen in Asia. Symptoms of the disease include clouding of the lens and visual impairment. Timely identification of the condition plays a crucial role in the management and outlook of pediatric patients.
OBJECTIVE: This investigation aimed to discover causative mutations in four separate Chinese family lineages.
METHODS: The detailed clinical data and family history of four Chinese families with autosomal dominant congenital cataracts were carefully documented. Examination of the Whole Exome Sequencing was utilized to identify the genetic anomalies present in the familial cases. Subsequent validation of the identified mutations was carried out using PCR and Sanger sequencing. Following this, various computational predictive programs were utilized to evaluate how the mutations impact the structure and function of the protein.
RESULTS: The sequencing results reveal four potential disease-causing mutations: c.436G > A (p.V146M) of CRYBB2 Family 1, c.26G > T (p.R9I) of GJA3 in family 2, c.227G > A (p.R76H) of GJA8 in family 3, c.-168G > T of FTL in family 4. Among them, the causative mutation in Family GJA3 is novel, and Family FTL is a rare cataract syndrome. These familial mutations showed complete co-segregation with the affected individuals, with no presence in unaffected family members or the 100 controls. Several bioinformatic prediction tools also support the likely pathogenicity of these mutations.
CONCLUSIONS: Our findings expand the mutational and phenotypic spectrum of genes associated with congenital cataracts and provide clues to the pathogenesis of congenital cataracts. These data also demonstrate the importance of NGS technology for the molecular diagnosis of congenital cataract patients.

OBJECTIVE: To develop a comprehensive compliance assessment scale for postoperative visual function rehabilitation in children with congenital cataracts and to assess its reliability and validity.
METHODS: Drawing on the Interactive Model of Health Behavior, we conducted a literature review and semi-structured interviews to create a pool of 36 items. The items underwent rigorous evaluation through the Delphi method, face validity checks, and item analysis, leading to a reduction to 18 items. To assess the scale\'s reliability and validity, we collected data from 225 parents of children with congenital cataracts. We employed SPSS version 25.0 for data analysis and evaluated construct validity using exploratory factor analysis, content validity, internal consistency reliability, and test-retest reliability.
RESULTS: The compliance scale for postoperative visual function rehabilitation in children with congenital cataracts comprises 5 dimensions and 18 items. Exploratory factor analysis extracted 5 common factors, with a cumulative variance contribution rate of 68.178%. Item-level content validity index ranged from 0.730 to 1.000, and the content validity index of the scale was 0.963. The total Cronbach\'s alpha coefficient, split-half reliability, and test-retest reliability of the scale were 0.855, 0.778, and 0.859, respectively.
CONCLUSIONS: The compliance assessment scale for postoperative visual function rehabilitation in children with congenital cataracts demonstrates acceptable reliability and validity. It serves as a valuable reference for developing standardized nursing programs for these children in clinical practice.

OBJECTIVE: To identify disease-causative mutations in families with congenital cataract.
METHODS: Two Chinese families with autosomal-dominant congenital cataract (ADCC) were recruited and underwent comprehensive eye examinations. Gene panel next-generation sequencing of common pathogenic genes of congenital cataract was performed in the proband of each family. Sanger sequencing was used to valid the candidate gene mutations and sequence the other family members for co-segregation analysis. The effect of sequence changes on protein structure and function was predicted through bioinformatics analysis. Major intrinsic protein (MIP)-wildtype and MIP-G29R plasmids were constructed and microinjected into zebrafish single-cell stage embryos. Zebrafish embryonic lens phenotypes were screened using confocal microscopy.
RESULTS: A novel heterozygous mutation (c.85G>A; p.G29R) in the MIP gene was identified in the proband of one family. A known heterozygous mutation (c.97C>T; p.R33C; rs864309693) in MIP was found in the proband of another family. In-silico prediction indicated that the novel mutation might affect the MIP protein function. Zebrafish embryonic lens was uniformly transparent in both wild-type PCS2+MIP and mutant PCS2+MIP.
CONCLUSIONS: Two missense mutations in the MIP gene in Chinese cataract families are identified, and one of which is novel. These findings expand the genetic spectrum of MIP mutations associated with cataracts. The functional studies suggest that the novel MIP mutation might not be a gain-of-function but a loss-of-function mutation.

OBJECTIVE: To establish a classification for congenital cataracts that can facilitate individualized treatment and help identify individuals with a high likelihood of different visual outcomes.
METHODS: Consecutive patients diagnosed with congenital cataracts and undergoing surgery between January 2005 and November 2021 were recruited. Data on visual outcomes and the phenotypic characteristics of ocular biometry and the anterior and posterior segments were extracted from the patients\' medical records. A hierarchical cluster analysis was performed. The main outcome measure was the identification of distinct clusters of eyes with congenital cataracts.
RESULTS: A total of 164 children (299 eyes) were divided into two clusters based on their ocular features. Cluster 1 (96 eyes) had a shorter axial length (mean±SD, 19.44±1.68 mm), a low prevalence of macular abnormalities (1.04%), and no retinal abnormalities or posterior cataracts. Cluster 2 (203 eyes) had a greater axial length (mean±SD, 20.42±2.10 mm) and a higher prevalence of macular abnormalities (8.37%), retinal abnormalities (98.52%), and posterior cataracts (4.93%). Compared with the eyes in Cluster 2 (57.14%), those in Cluster 1 (71.88%) had a 2.2 times higher chance of good best-corrected visual acuity [<0.7 logMAR; OR (95%CI), 2.20 (1.25-3.81); P=0.006].
CONCLUSIONS: This retrospective study categorizes congenital cataracts into two distinct clusters, each associated with a different likelihood of visual outcomes. This innovative classification may enable the personalization and prioritization of early interventions for patients who may gain the greatest benefit, thereby making strides toward precision medicine in the field of congenital cataracts.

OBJECTIVE: To assess the incidence of secondary glaucoma in children following congenital cataract surgery.
METHODS: Systematic review and meta-analysis.
METHODS: The PubMed, Embase, Cochrane Library, and Web of Science databases were searched from inception through March 16, 2023. Studies reporting congenital cataract surgery and glaucoma were enrolled. The quality of the selected studies was assessed using the Newcastle Ottawa Scale, and data analysis was executed utilizing R software.
RESULTS: A total of 36 published studies with 3151 patients (4717 eyes) were included in the analysis. The incidence rate of glaucoma following congenital cataract surgery was 6.6% (95% CI: 3.9%, 9.9%). The incidence of secondary glaucoma in the primary intraocular lens (IOL) implantation group (3.3% [95% CI: 1.5%, 5.8%]) and the secondary IOL implantation group (3.5% [95% CI: 0%, 11.4%]) were lower compared to the aphakia group (13.5% [95% CI: 7.7%, 20.6%]). The incidence rate among children with congenital cataracts from Asia (6.9% [95% CI: 4.1%, 10.4%]) was higher than that in European children (0.9% [95% CI: 0%, 3.0%]; P < .01). A correlation was identified between the age at cataract surgery and the incidence of secondary glaucoma (P = .02).
CONCLUSIONS: This meta-analysis found that the incidence of secondary glaucoma following congenital cataract surgery is approximately 6.6%. Children with IOL implantation exhibit a lower incidence of secondary glaucoma, with a lower incidence noted in European children compared to their Asian counterparts. The age at cataract surgery is an important risk factor to consider.

UNASSIGNED: Congenital cataract is a common cause of blindness. Genetic factors always play important role.
UNASSIGNED: This study identified a novel missense variant (c.1412C>T (p.P471L)) in the EZR gene in a four-generation Chinese family with nuclear cataract by linkage analysis and whole-exome sequencing. A knockout study in zebrafish using transcription activator-like effector nucleases was carried out to gain insight into candidate gene function.
UNASSIGNED: Conservative and functional prediction suggests that the P-to-L substitution may impair the function of the human ezrin protein. Histology showed developmental delays in the ezrin-mutated zebrafish, manifesting as multilayered lens epithelial cells. Immunohistochemistry revealed abnormal proliferation patterns in mutant fish.
UNASSIGNED: The study suggests that ezrin may be involved in the enucleation and differentiation of lens epithelial cells.

UNASSIGNED: Congenital cataracts stand as the primary cause of childhood blindness globally, characterized by clouding of the eye\'s lens at birth or shortly thereafter. Previous investigations have unveiled that a variant in the V-MAF avian musculoaponeurotic-fibrosarcoma oncogene homolog (MAF) gene can result in Ayme-Gripp syndrome and solitary cataract. Notably, MAF mutations have been infrequently reported in recent years.
UNASSIGNED: In this investigation, we recruited a Chinese family with non-syndromic cataracts. Whole exome sequencing and Sanger sequencing were applied to scrutinize the genetic anomaly within the family.
UNASSIGNED: Through whole exome sequencing and subsequent data filtration, a new mutation (NM_005360, c.901T>C/p.Y301H) in the MAF gene was detected. Sanger sequencing validated the presence of this mutation in another affected individual. The p.Y301H mutation, situated in an evolutionarily preserved locus, was not detected in our 200 local control cohorts and various public databases. Additionally, multiple bioinformatic programs predicted that the mutation was deleterious and disrupted the bindings between MAF and its targets.
UNASSIGNED: Hence, we have documented a new MAF mutation within a Chinese family exhibiting isolated congenital cataracts. Our study has the potential to broaden the spectrum of MAF mutations, offering insights into the mechanisms underlying cataract formation and facilitating genetic counseling and early diagnosis for congenital cataract patients.