Spectrum of pathologic mitochondria DNA mutations in Chinese patients with Leber′s hereditary optic neuropathy / 中华眼底病杂志

Objective To investigate the spectrum of mitochondrial DNA (mtDNA) mutations in Chinese patients with Leber′s hereditary optic neuropathy (LHON). Methods The primary mtDNA mutations (G3460A?G11778A and T14484C) of 140 patients with LHON were detected by mutation-specific priming polymerase chain reaction (MSP-PCR), heteroduplex-single strand conformation polymorphism polymerase chain reaction (HA-SSCP), restriction fragment length polymorphisms (RFLP) and measurement of DNA sequence. The transmissibility of the patients′ stirps was analyzed. Results In the 140 patients with LHON, G11778A mtDNA primary mutation was found in 130 (92.9%), including 113 males and 17 females; G3460A mutation was found in 2 (1.4%) including 1 male and 1 female; G14484A mutation was found in 8 (5.7%) including 6 males and 2 females. Conclusion In Chinese patients with LHON, the incidence of G11778A mtDNA mutation is higher than that of G3460A and T14484C.

Primary studies on retinal proteome of rds and C3B mice by two-dimensional gel electrophoresis / 眼科新进展

Objective　To apply two-dimensional (2-D) gel electrophoresis to resolve specially expressed proteins related to retinitis pigmentosa (RP) in the retina of rds mice.Methods　Proteins, prepared from the retinas of rds mice and normal C3B mice at different ages, were separated by using two-dimensional electrophoresis and then analyzed by 2-DE imaging analyzer.Results　2-D gel electrophoresis was established for the retinal proteome analysis. Retinal neuronal tissue was lysed by using chemical lysis solution and ultrasonic. Using carrier ampholyte to set up pH gradient as first dimension and casting vertical 12% SDS-acylamide-bis slab as second dimension, the major retinal proteins showed maps of proteome on 2-D gels clearly. Retinal proteome of rds and C3B mice at 37d has different expressive patterns. Some proteins only expressed in the retina of rds mice while another only in the retina of C3B mice and others had different level between the two kinds of mice.Conclusion　2-D gel electrophoresis is effective to separate specially expressed retinal proteins. The expressed proteins in the rds retina are different in quality and quantity from that in the normal C3B mice.

Comparison of computer-photoscreening with non-cycloplegic retinoscopy for amblyopiogenic risk factors in children / 眼科新进展

Objective　To determine the sensitivity and specificity of using the computer-photoscreener and non-cycloplegic retinoscopy in the detection of amblyopiogenic factors in nine to fifty months old infants.Methods　Three hundred children whose ages range from nine to fifty months were screened with the computer-photoscreener and non-cycloplegic retinoscopy. With a masked standardized clinical assessment as the standard, an overall comparison of the results obtained with the two techniques revealed a sensitivity and specificity. Photoscreen images on the computer monitor screen were reviewed and analyzed immediately by two independent observers for indicators of amblyopiogenic risk factors. Simultaneously, the results were compared to the findings of a full ophthalmologic examination.Results　The computer-photoscreener revealed a sensitivity of 94.2% and specificity of 90.1%, and the non-cycloplegic retinocopy revealed a sensitivity of 85.7% and specificity of 81.1% for the detection of amblyopiogenic risk factors, including hyperopia (+2.75 D or more), myopia (-1.50 D or more), astigmatism (2.00 D or more),anisometropia (2.00 D or more), ocular misalignment (5 degrees or more), and media opacity (1.5mm or more). Conclusion　The computer-photoscreener offers an opportunity to identify problems that limit vision, and could provide a feasible and sufficiently reliable screening technique in infants and preschool children who can be screened successfully for amblyopiogenic risk factors.

Clinical characteristics and candidate gene mutational screening in children with cone and cone-rod dystrophy / 中华眼底病杂志

Objective To analyze the clinical characteristics and to screen for causative mutations in CRX and GUCY2D genes in children with cone or cone-rod dystrophy. Methods Clinical data and genomic DNA was collected from 18 children with cone or cone-rod dystrophy, aged from 4 months to 8 years. The coding sequence of the cone-rod homeobox (CRX) gene and two exons of the retinal-specific guanylate cyclase GUCY2D gene (exons 2 and 8) were analyzed by using polymerase chain reaction(PCR) and heteroduplex combined with single-strand conformational polymorphism (heteroduplex-SSCP) analysis. Results All of the 18 patients manifested obvious visual impairment. Nystagmus, photophobia and mild ocular fundus changes were found in 13, 8,and 7 cases respectively. Normal fundus was seen in 11 cases. The visual acuity was less than 0.3 in 4 cases and was unable to measure in the other 14 cases because they were too young. Clinical ocular manifestations between cone and cone-rod dystrophy were overlapped. Mutation in the CRX and GUCY2D genes was not detected in the 18 children with cone and cone-rod dystrophy. Conclusion Visual impairment appeared more early and obvious than fundus changes in children with cone or cone-rod dystrophy. Mutation in the CRX gene may not contribute to this series of patients with cone and cone-rod dystrophy.

SNPs analysis of the METTL4 gene in high myopia groups / 中国病理生理杂志

AIM: To investigate the single nucleotide polymorphisms (SNPs) in the METTL4 gene which was mapped to 18p11.31, and the relationship between the SNPs and high myopia. METHODS: Genomic DNA was collected from 71 control subjects and 177 individuals with high myopia. Among them, there were 59 autosomal dominant high myopia probands (AD group), 46 autosomal recessive probands (AR group) and 72 patients non-transmitted (SF group). The exons of METTL4 gene were analyzed by polymerase chain reaction, heteroduplex-single strand conformation polymorphism (HA-SSCP) and sequencing. RESULTS: There were 2 SNPs of METTL4 gene in high myopia individuals and control subjects: SNP7438A→C, Glu230Asp, which hadn't been reported in GenBank;and SNP131C→A, Gln310Lys. SNP7438A→C genotypes between controls and high myopia groups were not different. SNP131C→A genotypes between controls and AR or SF groups were not different, while SNP131C→A genotypes showed a significant difference between AD group and control subjects. CONCLUSION: In METTL4 gene, SNP7438A→C is not responsible for high myopia. Further studies are needed to confirm whether SNP131C→A is responsible for autosomal dominant high myopia.

A missense mutation outside the large pocket of the retinoblastoma protein / 中国病理生理杂志

AIM: To understand the effect of the RB1 gene mutation on the function of pRB (the protein product of the RB1 gene) in the patients with retinoblastoma (RB). METHODS: The genomic DNA from retinoblastoma patients was extracted. After amplification, the promoter and all 27 exons were screened by SSCP-heteroduplex method. The mutation was cloned and identified by sequencing. The effect of the mutation product on the function of pRB was analyzed. RESULTS: One missense mutations of the exon 4 of the RB1 gene was identified in the genomic DNA from RB patients. This mutation was outside the large pocket of the pRB. No mutation of the RB1 gene was found in the genome DNA of the patient's parents. This is the fourth report that there was a genome mutation located outside the large pocket of pRB in the RB patients. CONCLUSION: The amino-terminus of the pRB may be essential for growth suppression.