Efficacy of locally produced Latanoprost in the control of intraocular pressure in patients with primary open-angle glaucoma.

PURPOSE: To determine the efficacy of locally produced Latanoprost in reducing the intraocular pressure (IOP) in patients with Primary open-angle glaucoma (POAG). DESIGN: Open-label, non-comparative, observational case study with non-probability purposive sampling. METHODS: A total of 48 patients (94 eyes) of either gender were recruited from glaucoma clinic with the diagnosis of POAG, having IOP of more than 21 mmHg. Patients were commenced on locally produced Latanoprost (Vislat 0.005%). IOP was subsequently measured at 4 weeks and 12 weeks, respectively. The primary end point was reduction in IOP at 12 weeks after the initiation of treatment. RESULTS: A total of 48 patients (94 eyes) were recruited from glaucoma clinic. The average IOP of our patients at baseline was 28.6 ± 8.1 mmHg, decreasing to 21.3 ± 10.6 mmHg at 4 weeks, indicating a drop of 19.1% (P < 0.001). IOP further decreased to 20.3 ± 8.7 mmHg after 3 months of treatment indicating a decrease of 23.3% (P < 0.001). A decrease in IOP occurred in 51 eyes (71.8%) at 4 weeks after treatment, improving to 54 eyes (76%) at 3-month follow-up. Twenty eyes (28.1%) did not show any change in IOP at 4 weeks. However, after 3-month follow-up only 17 eyes (23.9%) did not reveal any change in IOP. CONCLUSION: Our results showed a decrease in IOP of 19.1% after 4 weeks, increasing to 23.3% at 12 weeks in cohort of 37 patients (72 eyes) treated with locally produced Latanoprost (Vislat 0.005%).

Mutations in GRM6 identified in consanguineous Pakistani families with congenital stationary night blindness.

PURPOSE: This study was undertaken to investigate the causal mutations responsible for autosomal recessive congenital stationary night blindness (CSNB) in consanguineous Pakistani families. METHODS: Two consanguineous families with multiple individuals manifesting symptoms of stationary night blindness were recruited. Affected individuals underwent a detailed ophthalmological examination, including fundus examination and electroretinography. Blood samples were collected and genomic DNA was extracted. Exclusion analyses were completed by genotyping closely spaced microsatellite markers, and two-point logarithm of odds (LOD) scores were calculated. All coding exons, along with the exon-intron boundaries of GRM6, were sequenced bidirectionally. RESULTS: According to the medical history available to us, affected individuals in both families had experienced night blindness from the early years of their lives. Fundus photographs of affected individuals in both the families appeared normal, with no signs of attenuated arteries or bone spicule pigmentation. The scotopic electroretinogram (ERG) response were absent in all of the affected individuals, while the photopic measurements show reduced b-waves. During exclusion analyses, both families localized to a region on chromosome 5q that harbors GRM6, a gene previously associated with autosomal recessive CSNB. Bidirectional sequencing of GRM6 identified homozygous single base pair changes, specifically c.1336C>T (p.R446X) and c.2267G>A (p.G756D) in families PKRP170 and PKRP172, respectively. CONCLUSIONS: We identified a novel nonsense and a previously reported missense mutation in GRM6 that were responsible for autosomal recessive CSNB in patients of Pakistani decent.

Splice-site mutations identified in PDE6A responsible for retinitis pigmentosa in consanguineous Pakistani families.

PURPOSE: This study was conducted to localize and identify causal mutations associated with autosomal recessive retinitis pigmentosa (RP) in consanguineous familial cases of Pakistani origin. METHODS: Ophthalmic examinations that included funduscopy and electroretinography (ERG) were performed to confirm the affectation status. Blood samples were collected from all participating individuals, and genomic DNA was extracted. A genome-wide scan was performed, and two-point logarithm of odds (LOD) scores were calculated. Sanger sequencing was performed to identify the causative variants. Subsequently, we performed whole exome sequencing to rule out the possibility of a second causal variant within the linkage interval. Sequence conservation was performed with alignment analyses of PDE6A orthologs, and in silico splicing analysis was completed with Human Splicing Finder version 2.4.1. RESULTS: A large multigenerational consanguineous family diagnosed with early-onset RP was ascertained. An ophthalmic clinical examination consisting of fundus photography and electroretinography confirmed the diagnosis of RP. A genome-wide scan was performed, and suggestive two-point LOD scores were observed with markers on chromosome 5q. Haplotype analyses identified the region; however, the region did not segregate with the disease phenotype in the family. Subsequently, we performed a second genome-wide scan that excluded the entire genome except the chromosome 5q region harboring PDE6A. Next-generation whole exome sequencing identified a splice acceptor site mutation in intron 16: c.2028-1G>A, which was completely conserved in PDE6A orthologs and was absent in ethnically matched 350 control chromosomes, the 1000 Genomes database, and the NHLBI Exome Sequencing Project. Subsequently, we investigated our entire cohort of RP familial cases and identified a second family who harbored a splice acceptor site mutation in intron 10: c.1408-2A>G. In silico analysis suggested that these mutations will result in the elimination of wild-type splice acceptor sites that would result in either skipping of the respective exon or the creation of a new cryptic splice acceptor site; both possibilities would result in retinal photoreceptor cells that lack PDE6A wild-type protein. CONCLUSIONS: we report two splice acceptor site variations in PDE6A in consanguineous Pakistani families who manifested cardinal symptoms of RP. Taken together with our previously published work, our data suggest that mutations in PDE6A account for about 2% of the total genetic load of RP in our cohort and possibly in the Pakistani population as well.

AIPL1 implicated in the pathogenesis of two cases of autosomal recessive retinal degeneration.

PURPOSE: To localize and identify the gene and mutations causing autosomal recessive retinal dystrophy in two consanguineous Pakistani families. METHODS: Consanguineous families from Pakistan were ascertained to be affected with autosomal recessive retinal degeneration. All affected individuals underwent thorough ophthalmologic examinations. Blood samples were collected, and genomic DNA was extracted using a salting out procedure. Genotyping was performed using microsatellite markers spaced at approximately 10 cM intervals. Two-point linkage analysis was performed with the lod score method. Direct DNA sequencing of amplified genomic DNA was performed for mutation screening of candidate genes. RESULTS: Genome-wide linkage scans yielded a lod score of 3.05 at θ=0 for D17S1832 and 3.82 at θ=0 for D17S938, localizing the disease gene to a 12.22 cM (6.64 Mb) region flanked by D17S1828 and D17S1852 for family 61032 and family 61227, which contains aryl hydrocarbon receptor interacting protein-like 1 (AIPL1), a gene previously implicated in recessive Leber congenital amaurosis and autosomal dominant cone-rod dystrophy. Sequencing of AIPL1 showed a homozygous c.773G>C (p.Arg258Pro) sequence change in all affected individuals of family 61032 and a homozygous c.465G>T (p.(H93_Q155del)) change in all affected members of family 61227. CONCLUSIONS: The results strongly suggest that the c.773G>C (p.R258P) and c.465G>T (p.(H93_Q155del)) mutations in AIPL1 cause autosomal recessive retinal degeneration in these consanguineous Pakistani families.

Mutations in RLBP1 associated with fundus albipunctatus in consanguineous Pakistani families.

OBJECTIVE: To identify disease-causing mutations in two consanguineous Pakistani families with fundus albipunctatus. METHODS: Affected individuals in both families underwent a thorough clinical examination including funduscopy and electroretinography. Blood samples were collected from all participating members and genomic DNA was extracted. Exclusion analysis was completed with microsatellite short tandem repeat markers that span all reported loci for fundus albipunctatus. Two-point logarithm of odds (LOD) scores were calculated, and coding exons and exon-intron boundaries of RLBP1 were sequenced bi-directionally. RESULTS: The ophthalmic examination of affected patients in both families was consistent with fundus albipunctatus. The alleles of markers on chromosome 15q flanking RLBP1 segregated with the disease phenotype in both families and linkage was further confirmed by two-point LOD scores. Bi-directional sequencing of RLBP1 identified a nonsense mutation (R156X) and a missense mutation (G116R) that segregated with the disease phenotype in their respective families. CONCLUSIONS: These results strongly suggest that mutations in RLBP1 are responsible for fundus albipunctatus in the affected individuals of these consanguineous Pakistani families.

Mapping of a new locus associated with autosomal recessive congenital cataract to chromosome 3q.

PURPOSE: To localize the disease interval for autosomal recessive congenital cataracts in a consanguineous Pakistani family. METHODS: All affected individuals underwent detailed ophthalmologic examination. Blood samples were collected and genomic DNA was extracted. A genome-wide scan was performed with fluorescently-labeled microsatellite markers on genomic DNA from affected and unaffected family members and logarithm of odds (LOD) scores were calculated. RESULTS: Clinical records and ophthalmological examinations suggested that affected individuals have bilateral congenital cataracts. Genome-wide linkage analysis localized the critical interval to chromosome 3q with a maximum LOD score of 3.87 at θ=0; with marker D3S3609. Haplotype analyses refined the critical interval to a 23.39 cM (18.01 Mb) interval on chromosome 3q, flanked by D3S1614 proximally and D3S1262, distally. CONCLUSIONS: Here, we report a new locus for autosomal recessive congenital cataract localized to chromosome 3q in a consanguineous Pakistani family.

Autosomal recessive congenital cataract linked to EPHA2 in a consanguineous Pakistani family.

PURPOSE: To investigate the genetic basis of autosomal recessive congenital cataracts in a consanguineous Pakistani family. METHODS: All affected individuals underwent a detailed ophthalmological and clinical examination. Blood samples were collected and genomic DNAs were extracted. A genome-wide scan was performed with polymorphic microsatellite markers. Logarithm of odds (LOD) scores were calculated, and Eph-receptor type-A2 (EPHA2), residing in the critical interval, was sequenced bidirectionally. RESULTS: The clinical and ophthalmological examinations suggested that all affected individuals have nuclear cataracts. Genome-wide linkage analyses localized the critical interval to a 20.78 cM (15.08 Mb) interval on chromosome 1p, with a maximum two-point LOD score of 5.21 at theta=0. Sequencing of EPHA2 residing in the critical interval identified a missense mutation: c.2353G>A, which results in an alanine to threonine substitution (p.A785T). CONCLUSIONS: Here, we report for the first time a missense mutation in EPHA2 associated with autosomal recessive congenital cataracts.

Mapping of a novel locus associated with autosomal recessive congenital cataract to chromosome 8p.

PURPOSE: To identify the disease locus for autosomal recessive congenital cataracts in a consanguineous Pakistani family. METHODS: All affected individuals underwent a detailed ophthalmologic examination. Blood samples were collected and genomic DNA was extracted. A genome-wide scan was completed with fluorescently-labeled microsatellite markers on genomic DNA from affected and unaffected family members. Logarithms of odds (LOD) scores were calculated under a fully penetrant autosomal recessive model of inheritance. RESULTS: Ophthalmic examination suggested that affected individuals have bilateral cataracts. Linkage analysis localized the critical interval to chromosome 8p with LOD scores of 3.19, and 3.08 at θ=0, obtained with markers D8S549 and D8S550, respectively. Haplotype analyses refined the critical interval to 37.92 cM (16.28 Mb) region, flanked by markers, D8S277 proximally and D8S1734 distally. CONCLUSIONS: Here, we report a new locus for autosomal recessive congenital cataract mapped to chromosome 8p in a consanguineous Pakistani family.