Clinical and molecular genetic study of a Chinese Han family with X-linked retinoschisis / 中华实验眼科杂志

Objective:To study the clinical phenotype and molecular genetic characteristics of a Chinese Han family with X-linked retinoschisis (XLRS), and to determine the associated gene variations.Methods:A pedigree investigation was performed.The clinical characteristics and pedigree analysis of a Han Chinese family line with XLRS was conducted in August 2021 at the Xiamen Eye Center Affiliated to Xiamen University.All patients and the carriers underwent comprehensive medical history collection and routine ophthalmological examinations, including visual acuity, non-contact tonometer, slit lamp microscope, direct ophthalmoscope, and optical coherence tomography.The proband and some patients underwent medical optometry, fundus photography or wide-angle fundus photography, and electroretinogram examination.Peripheral venous blood samples were collected from the family members, and whole exome sequencing (WES) analysis was performed on the proband samples.For variants screened by WES, the expanded verification in other patients and normal persons in the family was carried out by Sanger sequencing.Multiple bioinformatic tools were used to analyze the pathogenicity of variants.This study protocol was approved by the Ethics Committee of Xiamen Eye Center of Xiamen University (No.XMYKZX-KY-2021-012). Written informed consent forms were obtained from each subject or guardian of minors.CADD, FATHMM and other bioinformatics tools were used to analyze the pathogenicity of the variation sites.Results:The Han XLRS pedigree consisted of 8 individuals in 3 generations.Out of the 3 cases diagnosed with XLRS based on clinical evaluation, all were male.The mother of the proband was a carrier of related genes.There were 5 persons with normal phenotypes.There was no history of consanguineous marriages within the family, and the disease was shown to be intergenerational, which is consistent with the recessive inheritance of the X chromosome.None of the patients had a history of systemic disease or any other abnormal manifestations.The prevailing feature of ophthalmopathy was poor binocular vision since childhood.The proband and his younger brother had spoke split in the macula, and their grandfather showed atrophy of retinal nerve fibers.Genetic analysis revealed a hemizygous variation c. 214G>C: p.Glu72Gln in the RS1 gene in all the patients in this family.The proband's mother was heterozygous at this site, and all other phenotypically normal family members exhibited wild type at this site.This variant was predicted to be a deleterious variation and likely to cause disease based on bioinformatics analysis. Conclusions:The proband and patients in this Han Chinese family have the known c. 214G>C: p.Glu72Gln hemizygous variation of the RS1 gene and exhibit mild XLRS, which was consistent with the recessive inheritance of X chromosome.

New mutation site c.361C > T of RS1 gene in X-linked retinoschisis / 中华眼底病杂志

Objective:To study the characteristics of the genotype and phenotypic in a family with X-linked retinoschisis (XLRS) due to RS1 mutation. Methods:A retrospective clinical study. An XLRS family of 4 generations of 26 people were included in the study. Among them, 8 participants were males and 7 participants were females. Routine ophthalmologic examination was performed on 3 patients in the family including the proband and 12 patients with normal phenotype. Optical coherence tomography was performed in 2 of the 3 patients. Peripheral venous blood was extracted from all participants, whole-genome DNA was extracted, and potential pathogenic genes were screened by Panel sequencing. Conservative analysis, pathogenicity analysis and protein structure prediction were carried out by software tools. The pathogenicity of gene mutations was analyzed according to the American Society of Medical Genetics and Genomics (ACMG) guidelines.Results:The proband was 3 years old. Optical coherence tomography (OCT) examination showed that the retinal core layer in the macular area of both eyes had a cystic change, which was segmented by vertical or oblique bridging tissue. The proband's uncle was 32 years old. OCT examination showed atrophy in the macular area of the left eye. The macular area of the right eye was cystoid, segmented by vertical or oblique bridging tissue. No abnormality was found in the fundus examination of the proband's parents and 10 members of his family. Panel sequencing showed that c.361C>T/ p.Q121X hemizygous mutation was found in the fifth exon of RS1 gene in the proband (Ⅳ3) and 2 patients (Ⅱ1, Ⅲ8). The mother was a heterozygous mutation carrier of the gene, while the father had no mutation. The mutant gene causes premature termination of RS1, a truncated protein encoding 224 amino acids to 120 amino acids. Of the 10 patients with normal fundus examination, 6 participants were normal. The mutation was carried by four people, which were women. Homology analysis of the protein sequence showed that the mutant site was highly conserved in 12 mammals. Three-dimensional structural analysis of RS1 protein showed that the c-terminal amino acid sequence of the mutant protein was more than 50% missing. Analysis of ACMG guidelines indicated that the mutation was pathogenic. Conclusion:The RS1 mutation site c.361C>T/p.Q121X is a new mutation site of XLRS.

Management of pediatric canalicular lacerations with the RS-1 silicone tube and the conventional silicone tube / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To evaluate the clinical effecacy of the RS-1 silicone tube and the conventional silicone tube in the management of pediatric canalicular lacerations.<p>METHODS: We retrospectively reviewed the medical records of 48 pediatric patients(48 eyes)with canalicular lacerations admitted for primary repair in the Department of Ocular Trauma of Hebei Eye Hospital from January 2015 to June 2018. The patients were divided into two groups according to the treatment of method: Group A(25 patients, the conventional silicone tube), Group B(23 patients, the RS-1 silicone tube). The management of pediatric canalicular lacerations were performed under general anesthesia. The silicone tube was removed about 3mo after surgery. The surgical time, clinical efficacy and complications were compared.<p>RESULTS: The mean surgical time between the two groups was 44.92±14.45min in Group A and 31.78±7.40min in Group B, which was statistically significant difference(<i>t</i>=4.02, <i>P</i><0.01). The clinical efficacy of the two groups was compared. Group A: 20 patients were cured(80%), 2 patients were improved(8%), 3 patients were failed(12%), and the functional success rate was 88%. Group B: 19 patients were cured(82%), 2 patients were improved(9%), 2 patients were failed(9%), the functional success rate was 91%, which was not statistically significant difference(χ2=0.14, <i>P</i>>0.05). The incidence of complications(32% <i>vs</i> 9%)including lower lacrimal point and mild eyelid eversion(1 patient 4% <i>vs</i> 1 patient 4%), slit canaliculus(2 patients 8% <i>vs</i> 1 patient 4%), early tube extrusion(3 patients 12% <i>vs</i> 0%), and nasal mucosal injury(3 patients 12% <i>vs</i> 0%)in Groups A and B, respectively, were comparable. There was statistically significant difference in the incidence of complications between the groups(χ2=3.94, <i>P</i><0.05).<p>CONCLUSION: There is no statistically significant difference with the two different types of silicone tube, which have good clinical efficacy, in the management of pediatric canalicular lacerations. But the RS-1 silicone tube is easier to operate, shorter surgical time, less complications and easier to removed.

Molecular characterization of a rare phenotype of X-linked retinoschisis with angle-closure glaucoma

A 11-year-old boy presented with complaints of blurred vision and on evaluation was found to have X-linked retinoschisis (XLRS) with angle-closure glaucoma. Clinical and genetic evaluation of first-degree family members was done. His brother had a milder form of XLRS with shallow anterior chamber. Topical dorzolamide 2% and timolol 0.5% were used to control intraocular pressure. Genetic analysis revealed a novel three base pair deleterious mutation (c. 375_377 del AGA) in exon-5 of the RS1 gene in three members of the family.

RS-1 enhanced the efficiency of CRISPR-Cas9 mediated knock-in of human lactoferrin / 生物工程学报

This study aims to knock out the goat β-lactoglobulin (BLG) gene using CRISPR-Cas9 system and knock in human lactoferrin (hLF) at the BLG locus, and further study the effect of RAD51 stimulatory compound (RS-1) on homologous recombination efficiency. First, we designed an sgRNA targeting the first exon of goat BLG gene and constructed a co-expression vector pCas9-sgBLG. This sgRNA vector was then transfected into goat ear fibroblasts (GEFs), and the target region was examined by T7EN1 assay and sequencing. Second, we constructed a targeting vector pBHA-hLF-NIE including NEO and EGFP genes based on BLG gene locus. This targeting vector together with pCas9-sgBLG expression vector was co-transfected into GEFs. Transfected cells were then treated with 0, 5, 10 and 20 μmol/L RS-1 for 72 h to analyse the EGFP expression efficiency. Next, we used 800 μg/mL G418 to screen G418-resistent cell clones, and studied hLF site-specific knock-in cell clones by PCR and sequencing. The editing efficiency of sgBLG was between 25% and 31%. The EGFP expression efficiency indicated that the gene knock-in efficiency was improved by RS-1 in a dose-dependent manner, which could reach 3.5-fold compared to the control group. The percentage of positive cells with hLF knock-in was increased to 32.61% when 10 μmol/L RS-1 was used. However, when the concentration of RS-1 increased to 20 μmol/L, the percentage of positive cells decreased to 22.22% and resulted in an increase of senescent cell clone number. These results suggested that hLF knock-in and BLG knock-out in GEFs were achieved by using CRISPR/Cas9 system, and optimum concentration of RS-1 could improve knock-in efficiency, which provides a reference for efficiently obtaining gene knock-in cells using CRISPR/Cas9 in the future.

IDENTIFICATION OF HUMAN MURR1, THE HOMOLOGUE OF MOUSE IMPRINTED Murr1 GENE / 药物分析学报

Objective To identify the mRNA sequence, genetic construction, imprinting status, and expression profile of human MURR1 gene, the homologue of mouse imprinted Murr1 gene. Methods The MURR1 mRNA sequence was identified by colony hybridization screening of human cDNA library and the 5'-RACE analyses; Absence of U2AF1-RS1 gene within MURR1 was confirmed by Southern Blotting; Expression profile of MURR1 was examined by Northern Blotting; The imprinting status of MURR1 were revealed by SNP investigation and RT-PCR followed by sequencings and RFLP analyses. Results The full-length mRNA sequence of MURR1 spans 711 bp, transcribed from 3 exons, encodes predicted MURR1 protein of 190 amino acids. The gene was expressed in all the 12 kinds of human adult tissues and 6 kinds of fetal tissues. It showed biallelic expression in all 32 investigated samples including 6 kinds of human fetal tissues and 8 adult brains. Unlike mouse imprinted U2af1-rs1 gene existing in the intron of Murr1, the human U2AF1-RS1 gene was not located in the MURR1 locus. Conclusion Human MURR1 gene is not imprinted and the non-imprinting is possible due to the absence of human homologue of mouse U2af1-rs1 within MURR1 locus.