Genetic Basis of Primary Angle Closure Glaucoma: The Role of Collagens and Extracellular Matrix

This is an Editorial and does not have an abstract

Myocilin Mutations Are Not a Major Cause of Primary Congenital Glaucoma in Iranian Patients

Purpose: To assess the frequency of mutations in the Myocilin (MYOC) gene in Iranian patients affected with primary congenital glaucoma (PCG). Methods: The individuals evaluated herein are among a larger cohort of 100 patients who had previously been screened for CYP1B1 mutations. Eighty subjects carried mutations in CYP1B1, but the remaining 20 patients who did not, underwent screening for MYOC mutations for the purpose of the study. MYOC exons in the DNA were polymerase chain reaction (PCR) amplified and sequenced. Sequencing was performed using PCR primers, the ABI big dye chemistry and an ABI3730XL instrument. Sequences were analyzed by comparing them to reference MYOC sequences using the Sequencher software. Results: Four MYOC sequence variations were observed among the patients, but none of them were considered to be associated with disease status. Three of these variations were single nucleotide polymorphisms already reported not to be disease causing, the fourth variation created a synonymous codon and did not affect any amino acid change. Conclusion: In this cohort, MYOC mutations were not observed in any Iranian subject with PCG. It is possible that in a larger sample, a few subjects carrying disease causing MYOC mutations could have been observed. But our results show that the contribution of MYOC to PCG status in Iran is small if any

Mutation Screening of Six Exons of ABCA4 in Iranian Stargardt Disease Patients

Purpose: Stargardt disease type 1 (STGD1) is a recessively inherited retinal disorder that can cause severe visual impairment. ABCA4 mutations are the usual cause of STGD1. ABCA4 codes a transporter protein exclusively expressed in retinal photoreceptor cells. The gene contains 50 exons. Mutations are most frequent in exons 3, 6, 12, and 13, and exons 10 and 42 each contain two common variations. We aimed to screen these exons for mutations in Iranian STGD1 patients. Methods: Eighteen STGD1 patients were recruited for genetic analysis. Diagnosis by retina specialists was based on standard criteria, including accumulation of lipofuscin. The six ABCA4 exons were PCR amplified and sequenced by the Sanger method. Results: One or more ABCA4-mutated alleles were identified in 5 of the 18 patients (27.8%). Five different mutations including two splice site (c.1356+1G>A and c.5836-2A>G) and three missense mutations (p.Gly1961Glu, p.Gly1961Arg, and p.Gly550Arg) were found. The p.Gly1961Glu mutation was the only mutation observed in two patients. Conclusion: As ABCA4 mutations in exons 6, 12, 10, and 42 were identified in approximately 25% of the patients studied, these may be appropriate exons for screening projects. As in other populations, STDG1 causative ABCA4 mutations are heterogeneous among Iranian patients, and p.Gly1961Glu may be relatively frequent

Kavosh: a new algorithm for finding network motifs

<p>Abstract</p> <p>Background</p> <p>Complex networks are studied across many fields of science and are particularly important to understand biological processes. Motifs in networks are small connected sub-graphs that occur significantly in higher frequencies than in random networks. They have recently gathered much attention as a useful concept to uncover structural design principles of complex networks. Existing algorithms for finding network motifs are extremely costly in CPU time and memory consumption and have practically restrictions on the size of motifs.</p> <p>Results</p> <p>We present a new algorithm (Kavosh), for finding k-size network motifs with less memory and CPU time in comparison to other existing algorithms. Our algorithm is based on counting all k-size sub-graphs of a given graph (directed or undirected). We evaluated our algorithm on biological networks of <it>E. coli </it>and <it>S. cereviciae</it>, and also on non-biological networks: a social and an electronic network.</p> <p>Conclusion</p> <p>The efficiency of our algorithm is demonstrated by comparing the obtained results with three well-known motif finding tools. For comparison, the CPU time, memory usage and the similarities of obtained motifs are considered. Besides, Kavosh can be employed for finding motifs of size greater than eight, while most of the other algorithms have restriction on motifs with size greater than eight. The Kavosh source code and help files are freely available at: <url>http://Lbb.ut.ac.ir/Download/LBBsoft/Kavosh/</url>.</p

Erratum – Carrier Status for p.Gly61Glu and p.Arg368His CYP1B1 Mutations Causing Primary Congenital Glaucoma in Iran

This is an Erratum to "Carrier Status for p.Gly61Glu and p.Arg368His CYP1B1 Mutations Causing Primary Congenital Glaucoma in Iran" [J Ophthalmic Vis Res 2021;16(4):574–581] and does not have an abstract. Please download the PDF or view the article HTML

Carrier Status for p.Gly61Glu and p.Arg368His CYP1B1 Mutations Causing Primary Congenital Glaucoma in Iran

Purpose: To estimate carrier frequencies of CYP1B1 mutations p.Gly61Glu and p.Arg368His, respectively, in Talesh and the east of Guilan province in Iran with a maximum error of 2%. Previously, it was shown that these CYP1B1 mutations may be relatively prevalent in these regions. Methods: Population-based screenings were performed. DNA was extracted from saliva samples of 1036 individuals from Talesh and 3029 individuals from the east of Guilan. P.Gly61Glu and p.Arg368His screenings were performed, respectively, by RFLP and ARMS-based PCR protocols. For confirmation, the DNA of individuals with mutations was sequenced using the Sanger protocol. Results: Nine individuals from Talesh (0.86%; 95%CI: 0.45–1.64%) carried the p.Gly61Glu mutation, and 73 from the east of Guilan (2.41%; 95%CI: 1.91–3.04%) carried p.Arg368His. There was no significant difference in frequencies between urban and rural regions of the various cities, nor among four cities within the east of Guilan. Conclusion: The frequencies of p.Gly61Glu carriers in Talesh and of p.Arg368His carriers in the east of Guilan were within the 95% confidence interval of a previous study based on screenings of fewer individuals. The reliability of the recent estimates is higher, as the confidence interval for p.Gly61Glu decreased from 6.5% to 1.19% and the interval for p.Arg368His decreased from 4% to 1.13%. Based on the new findings, the maximum expected frequency of p.Gly61Glu carriers in Talesh is 1.64%, and of p.Arg368His carriers in the east of Guilan is 3%. The need for performing premarital screenings in the respective cities can be evaluated