ABSTRACT
Objective:To analyze the genotype of hereditary eye diseases with early-onset high myopia (eoHM) and its relationship with phenotype.Methods:The families with eoHM were collected in Ningxia Eye Hospital from January 2019 to June 2020.The medical records of the probands and their family members were inquired and recorded in detail, and the relevant ocular examinations were performed.Peripheral venous blood samples were collected from patients and their family members, and whole-genome DNA was extracted.Sequence capture sequencing technology was applied to screen for disease-causing gene mutations in probands.The detected suspected pathogenic variants were verified by Sanger sequencing and were analyzed by family cosegregation analysis.According to ACMG guidelines, the pathogenicity of novel variants was evaluated.The original literature about hereditary eye diseases with eoHM was searched to analyze the relationship between mutated genes and clinical phenotype.This study protocol adhered to the Declaration of Helsinki.All subjects or their guardians were informed of the purpose and procedure of the study and signed the informed consent form.The study protocol was approved by the Ethics Committee of the People's Hospital of Ningxia Hui Autonomous Region (No.2016018).Results:A total of 20 eoHM families were collected, among which pathogenic variants associated with inherited eye diseases were detected in 8 families.Of the 8 probands, two were diagnosed with familial exudative vitreoretinopathy, one with X-linked retinitis pigmentosa, one with congenital stationary nightblindness, one with Stickler syndrome, one with achromatopsia, one with Leber congenital amaurosis, and one with gyrate atrophy of the choroid and retina.The first diagnosis age of the 8 probands was 4-7 years old, and they were all diagnosed as high myopia, with a refractive status ≤-6.00 DS.Genetic tests showed that the 8 probands carried a heterozygous variant c. 313A>G (p.M105Val) in FZD4 gene, a heterozygous variant c. 14_15insAAGA (p.Asp5fs *) in TSPAN12 gene, a heterozygous frameshift variant c. 2234_2237del (p.Arg745fs) in RPGR gene, a compound heterozygous variant of c. 481C>T (p.Gln161Ter *) and c. 355>T (p.Arg119Cys *) in GPR179 gene, a frameshift variant c. 1659_1660insACGGTGACCCTGGCCGTCCTGG (p.Pro554fs *) in COL2A1 gene, a compound heterozygous variant of c. 1811C>T (p.Thr604Ile *) and c. 967G>A (p.Gly323Ser) in PDE6B gene, a compound heterozygous variant of c. 604_619delTCCACGGCACTCAGGG (p.Ser202fs *) and c. 995G>C (p.Arg332Pro) in GUCY2D gene, a homozygous variant c. 772C>T (p.Pro241Leu) in OAT gene.Seven of them were novel variants.Compared with the previous literature, the clinical and gene phenotypes of the 8 families were analyzed in detail in this study, which provided the basis for the diagnosis of hereditary eye diseases with eoHM. Conclusions:EoHM is closely related to some hereditary eye diseases, which may be the reason for the early diagnosis of children and an important clue for clinicians to detect potential hereditary eye diseases.Further clinical evaluations of ocular structure and function as well as genetic screening in children with eoHM are recommended.
ABSTRACT
Background Study determined that retinitis pigmentosa has a similar pathogenesis mechanism to Alzheimer disease,and activity of cyclin-dependent kinase 5 (Cdk5) and its activators participates in the degeneration of central nervous system.Roscovitine,an inhibitor of Cdk5,can suppress activity of Cdk5/p25 pathway and therefore inhibit cell apoptosis.However,the influence of roscovitine on retinitis pigmentosa(RP) is unclear.Objective This study was to investigate the expressions of p35,p25 and tau in the retinas of RCS rats.Methods Roscovitine of 4 μl was intravitreally injected in the right eyes of 12 SPF 17-day-old RCS rats,and the fellow eyes were not intervened as the control eyes.The rats were sacrificed on eighth day (postnatal 25 days) and eighteenth day (postnatal 35 days),and whole retinas were isolated to evaluate the relative expressions of Cdk5,p35,p25 and tau phosphorylation by Western blot,and the activity of Cdk5/p25 was analyzed by quantitative colorimetric assay.The results were compared between the right eyes and fellow eyes by paired t test.The use and care of the rats complied with Ethic Statement of Experimental Animal of Ningxia Medical University.Results In the eighth and eighteenth day after injection,the relative expression values (A values) of p35 in rat retinas were 1.186±0.019 and 1.069± 0.019 in the injected eyes,showing significant decreases in comparison with 1.364±0.016 and 1.214±0.008 of the fellow eyes (t =-6.294,-6.477,both at P＜0.05);the relative expression values (A values) of p25 in rat retinas were 0.312±0.009 and 0.269±0.018 in the injected eyes,which was significantly lower than 0.595±0.013 and 0.473±0.011 of the fellow eyes (t=-36.508,-11.879,both at P＜0.05).No significant difference was found in the relative expression of Cdk5 protein between the injected eyes and the fellow eyes in various time points after injection (both at P＞0.05).The activities of Cdk5/p25 were (0.003 83 ±0.000 14) mol/(s · mg) and (0.002 01 ± 0.000 11) mol/(s · mg) in the injected eyes,with significant decreases in comparison with the (0.005 47±0.000 27)mol/(s · mg)and (0.003 35±0.000 15) mol/(s · mg) of the fellow eyes (t=-9.152,P=0.000;t=-9.248,P=0.000),and the tau phosphorylation levels followed the same pattern in the eighth and eighteenth day after injection (t =-9.854,-6.744,both at P＜0.05).Conclusions Intravitreal injection of roscovitine can inhibit the activity of Cdk5/p25 and tau phosphorylation level in retinas of RCS rats to certain extend.