Understanding variable disease severity in X-linked retinoschisis: Does RS1 secretory mechanism determine disease severity?

X-linked retinoschisis (XLRS) is a retinal degenerative disorder caused by mutations in RS1 gene leading to splitting of retinal layers (schisis) which impairs visual signal processing. Retinoschisin (RS1) is an adhesive protein which is secreted predominantly by the photoreceptors and bipolar cells as a double-octameric complex. In general, XLRS patients show wide clinical heterogeneity, presenting practical challenges in disease management.

Analysis of candidate genes ZEB1 and LOXHD1 in late-onset Fuchs' endothelial corneal dystrophy in an Indian cohort.

Background: Fuchs' endothelial corneal dystrophy (FECD) is a complex degenerative disease of the corneal endothelium with genetic predisposition. Pathogenic rare variants have been identified in SLC4A11, LOXHD1, ZEB1, and AGBL1. Association of single nucleotide polymorphisms (SNPs) and CTG trinucleotide repeat expansions in the intron of TCF4 gene to FECD has been studied across multiple ethnicities.

Association of polymorphisms in the intron of gene to late-onset Fuchs endothelial corneal dystrophy: An Indian cohort study.

Purpose: Fuchs endothelial corneal dystrophy (FECD) is a progressive degenerative disease of the corneal endothelium. It is genetically heterogeneous and follows either an autosomal dominant or sporadic pattern of inheritance. Here, we have explored the association of four previously reported intronic single nucleotide polymorphisms and intronic CTG repeat expansions in TCF4 gene to FECD in an Indian cohort.

Homozygosity mapping guided next generation sequencing to identify the causative genetic variation in inherited retinal degenerative diseases.

Inherited retinal degeneration (IRD) are a group of genetically heterogeneous disease of which retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) are the most common and severe type. In our study we had taken three unrelated South Indian consanguineous IRD families. Homozygosity mapping was done using Affymetrix 250K Nsp1 GeneChip in each of LCA, Cone-Rod dystrophy (CRD) and autosomal recessive RP (arRP) families followed by targeted re-sequencing by next generation sequencing (NGS) on Illumina MiSeq.

Homozygosity Mapping in Leber Congenital Amaurosis and Autosomal Recessive Retinitis Pigmentosa in South Indian Families.

Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP) are retinal degenerative diseases which cause severe retinal dystrophy affecting the photoreceptors. LCA is predominantly inherited as an autosomal recessive trait and contributes to 5% of all retinal dystrophies; whereas RP is inherited by all the Mendelian pattern of inheritance and both are leading causes of visual impairment in children and young adults. Homozygosity mapping is an efficient strategy for mapping both known and novel disease loci in recessive conditions, especially in a consanguineous mating, exploiting the fact that the regions adjacent to the disease locus will also be homozygous by descent in such inbred children.

Biosynthetic and functional defects in newly identified SLC4A11 mutants and absence of COL8A2 mutations in Fuchs endothelial corneal dystrophy.

Late-onset Fuchs endothelial corneal dystrophy (FECD) shows genetic heterogeneity. Identification of SLC4A11 as a candidate gene for congenital hereditary endothelial dystrophy with similar corneal endothelial defects as FECD and reduced mRNA expression of SLC4A11 in the endothelium of FECD cases suggested that this gene may also be involved in pathogenesis of FECD. Mutations in SLC4A11 give rise to SLC4A11 protein marked by retention in the endoplasmic reticulum as a result of mis-folding.

Molecular profiling of complete congenital stationary night blindness: a pilot study on an Indian cohort.

Purpose: Congenital stationary night blindness (CSNB) is a non-progressive retinal disorder that shows genetic and clinical heterogeneity. CSNB is inherited as an autosomal recessive, autosomal dominant, or X-linked recessive trait and shows a good genotype-phenotype correlation. Clinically, CSNB is classified as the Riggs type and the Schubert-Bornschein type.

Leber's congenital amaurosis as the retinal degenerative phenotype in thiamine responsive megaloblastic anemia: a case report.

Background: Thiamine responsive megaloblastic anemia syndrome (TRMA), an autosomal recessive disorder is caused by mutations in the SLC19A2 gene which encodes for thiamine transporter 1 (THTR1) protein. TRMA presents with a triad of clinical features that includes diabetes mellitus, megaloblastic anemia and sensorineural hearing loss. Apart from the triad, reported ophthalmic features include cone rod dystrophy, optic atropy and retinitis pigmentosa.

Identification of a novel splice-site mutation in the Lebercilin (LCA5) gene causing Leber congenital amaurosis.

Purpose: Leber congenital amaurosis (LCA) is one of the most common causes of hereditary blindness in infants. To date, mutations in 13 known genes and at two other loci have been implicated in LCA causation. An examination of the known genes highlights several processes which, when defective, cause LCA, including photoreceptor development and maintenance, phototransduction, vitamin A metabolism, and protein trafficking.

Effect of oral supplementation of free amino acids in type 2 diabetic patients-- a pilot clinical trial.

Background: Oral amino acid intake reduces plasma glucose in Streptozotocin-induced diabetic rats. This study examined the effect of oral amino acid supplementation in patients with type 2 diabetes mellitus (DM).

Material/methods: A double blind pilot clinical trial was conducted for a period of 2 months on 77 subjects with type 2 DM.