Background High myopia (HM) refers to an eye refractive error exceeding −5.00 D, significantly elevating blindness risk. The underlying mechanism of HM remains elusive. Given the extensive genetic heterogeneity and vast genetic base opacity, it is imperative to identify more causative genes and explore their pathogenic roles in HM.
Methods We employed exome sequencing to pinpoint the causal gene in an HM family. Sanger sequencing was used to confirm and analyse the gene mutations in this family and 200 sporadic HM cases. Single-cell RNA sequencing was conducted to evaluate the gene’s expression patterns in developing human and mouse retinas. The CRISPR/Cas9 system facilitated the gene knockout cells, aiding in the exploration of the gene’s function and its mutations. Immunofluorescent staining and immunoblot techniques were applied to monitor the functional shifts of the gene mutations at the cellular level.
Results A suspected nonsense mutation (c.C172T, p.Q58X) in CCDC66 was found to be co-segregated with the HM phenotype in the family. Additionally, six other rare variants were identified among the 200 sporadic patients. CCDC66 was consistently expressed in the embryonic retinas of both humans and mice. Notably, in CCDC66-deficient HEK293 cells, there was a decline in cell proliferation, microtube polymerisation rate and ace-tubulin level. Furthermore, the mutated CCDC66 failed to synchronise with the tubulin system during Hela cell mitosis, unlike its wild type counterpart.
Conclusions Our research indicates that the CCDC66 variant c.C172T is associated with HM. A deficiency in CCDC66 might disrupt cell proliferation by influencing the mitotic process during retinal growth, leading to HM.
- Eye Diseases
- Genetics, Medical
- Genetic Variation
- Human Genetics
Data availability statement
Data are available upon reasonable request.
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XC and PT contributed equally.
Contributors Conceptualisation: QT, PT, XC, KX, ZH; Data curation: QT, XC, YJ, ZC, LZ; Formal analysis: QT, XC, YJ, ZC; Funding acquisition: QT, ZY, WL, KX, ZH; Investigation: QT, PT, YJ, ZC, LZ.; Methodology: QT, XC, YJ; Resources: QT, PT, XC, KX; Supervision: QT, KX, ZH; Visualisation: QT, XC, YJ; Writing—original draft: QT, XC, ZH; Writing—review and editing: QT, PT, XC, ZH. Guarantor: QT.
Funding This study was supported by the Key R&D Program of Hunan Province (grant number 2019SK2051, 2021SK1010), the National Natural Science Foundation of China (grant number 82271908, 82130043), the National Key R&D Program of China (grant number 2021YFA0805202), the Natural Science Foundation of Hunan Province (grant number 2021JJ40811).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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