Robert Ritter

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Age-related macular degeneration (AMD) is a common, late-onset, and complex trait with multiple risk factors. Concentrating on a region harboring a locus for AMD on 1q25-31, the ARMD1 locus, we tested single-nucleotide polymorphisms for association with AMD in two independent case-control populations. Significant association (P = 4.95 x 10(-10)) was(More)
Impaired spatial learning is a prominent deficit in fragile X syndrome (FXS). Previous studies using the Fmr1 knockout (KO) mouse model of FXS have not consistently reported a deficit in spatial learning. Fmr1 KO mice bred onto an albino C57BL/6J-Tyr(c-Brd) background showed significant deficits in several primary measures of performance during place(More)
PURPOSE Autosomal dominant Stargardt disease-3 (STGD3) is caused by mutations in elongase of very long chain fatty acids-4 (ELOVL4). The goal of this study was to generate and characterize heterozygous and homozygous knockin-mice that carry a human STGD3 pathogenic mutation in the mouse Elovl4 gene. METHODS Recombinant Stgd3-knockin mice were generated(More)
Cerebrolysin is a peptidergic nootropic drug with a multimodal mechanism of action. It is expected to have a positive influence on neurodegenerative diseases such as senile dementia of the Alzheimer type (SDAT). Experimental studies have shown Cerebrolysin to have a regulatory effect on energy metabolism, a positive influence on behavior through(More)
Stickler syndrome (progressive arthro-ophthalmopathy) is a genetically heterogeneous disorder resulting from mutations in at least three collagen genes. The most common disease-causing gene is COL2A1, a 54-exon-containing gene coding for type II collagen. At least 17 different mutations causing Stickler syndrome have been reported in this gene.(More)
PURPOSE To describe a novel gene causing a Stargardt-like phenotype in a family with dominant macular dystrophy and the exclusion of all known genes within the disease locus. METHODS Meiotic breakpoint mapping in a family of 2314 individuals enabled refinement of the location of the disease gene. The genomic organization and expression profile of known(More)
PURPOSE To report a novel sporadic PAX2 gene mutation in a child with atypical bilateral optic nerve coloboma and congenital renal hypoplasia. DESIGN Observational case report and experimental study. METHODS Mutational analysis of the PAX2 gene in a family. RESULTS A 9-year-old patient with a history of renal transplantation for congenital renal(More)
PURPOSE To describe the clinical features and identify the mutation responsible for an autosomal dominant vitreoretinal degeneration occurring in a previously unreported large family. DESIGN Cohort study. METHODS Family members were evaluated clinically over a 30-year period. Genealogical investigation, genetic linkage to known vitreoretinal(More)
PURPOSE To determine if levels of the glycocalyx membrane mucins, MUC1 and MUC16, and the secreted goblet cell mucin MUC5AC are altered in conjunctival cells and tears of postmenopausal women presenting with a history of non-Sjögren dry eye and if mucin levels correlate with dry eye clinical diagnostic data. METHODS Eighty-four postmenopausal women with a(More)
OBJECTIVES To characterize a disease-associated haplotype in 7 families with autosomal dominant Stargardt-like macular dystrophy and to determine whether these families share a common ancestor. METHODS Twenty-five polymorphic DNA markers spanning known dominant Stargardt-like gene loci were used to determine the haplotype associated with disease. In(More)