COL4A1 mutation in Axenfeld-Rieger anomaly with leukoencephalopathy and stroke.
ABSTRACT Several hereditary ischemic small-vessel diseases of the brain have been reported during the last decade. Some of them have ophthalmological, mainly retinal, manifestations. Herein, we report on a family affected by vascular leukoencephalopathy and variable abnormalities of the anterior chamber of the eye.
After the occurrence of a small, deep infarct associated with white matter lesions in a patient with a medical history of congenital cataract and amblyopia, we conducted clinical and neuroradiological investigations in 10 of her relatives.
Diffuse leukoencephalopathy associated with ocular malformations of the Axenfeld-Rieger type was observed in five individuals. Familial genetic analyses led to the identification of a novel missense mutation in the COL4A1 gene, p.G720D, which cosegregates with the disease.
Our data corroborate previous observations demonstrating the role of COL4A1 in cerebral microangiopathy and expand the phenotypic spectrum associated with mutations in this gene. We delineate a novel association between the Axenfeld-Rieger anomaly and leukoencephalopathy and stroke. Ann Neurol 2007.
- SourceAvailable from: Lucinda Craggs[Show abstract] [Hide abstract]
ABSTRACT: Small vessel diseases (SVDs) of the brain are likely to become increasingly common in tandem with the rise in the aging population. In recent years, neuroimaging and pathological studies have informed on the pathogenesis of sporadic SVD and several single gene (monogenic) disorders predisposing to subcortical strokes and diffuse white matter disease. However, one of the limitations toward studying SVD lies in the lack of consistent assessment criteria and lesion burden for both clinical and pathological measures. Arteriolosclerosis and diffuse white matter changes are the hallmark features of both sporadic and hereditary SVDs. The pathogenesis of the arteriopathy is the key to understanding the differential progression of disease in various SVDs. Remarkably, quantification of microvascular abnormalities in sporadic and hereditary SVDs has shown that qualitatively the processes involved in arteriolar degeneration are largely similar in sporadic SVD compared with hereditary disorders such as cerebral autosomal arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Important significant regional differences in lesion location within the brain may enable one to distinguish SVDs, where frontal lobe involvement appears consistently with almost every SVD, but others bear specific pathologies in other lobes, such as the temporal pole in CADASIL and the pons in pontine autosomal dominant microangiopathy and leukoencephalopathy or PADMAL. Additionally, degenerative changes in the vascular smooth muscle cells, the cerebral endothelium and the basal lamina are often rapid and more aggressive in genetic disorders. Further quantification of other microvascular elements and even neuronal cells is needed to fully characterize SVD pathogenesis and to differentiate the usefulness of vascular interventions and treatments on the resulting pathology.Brain Pathology 09/2014; 24(5). · 4.35 Impact Factor
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ABSTRACT: Background Almost one-third of congenital cataracts are primarily autosomal dominant disorders, which are also called autosomal dominant congenital cataract, resulting in blindness and clouding of the lens. The purpose of this study was to identify the disease-causing mutation in a Chinese family affected by bilateral, autosomal dominant congenital cataract.Methods The detection of candidate gene mutation and the linkage analysis of microsatellite markers were performed for the known candidate genes. Molecular mapping and cloning of candidate genes were used in all affected family members to screen for potential genetic mutations and the mutation was confirmed by single enzyme digestion.ResultsThe proband was diagnosed with isolated, congenital cataract without the typical clinical manifestations of cataract, which include diabetes, porencephaly, sporadic intracerebral hemorrhage, and glomerulopathy. A novel mutation, c.2345 G¿>¿C (Gly782Ala), in exon 31 of the collagen type IV ¿lpha1 (COL4A1) gene, which encodes the collagen alpha-1(IV) chain, was found to be associated with autosomal dominant congenital cataract in a Chinese family. This mutation was not found in unaffected family members or in 200 unrelated controls. Sequence analysis confirmed that the Gly782 amino acid residue is highly conserved.Conclusions The novel mutation (c.2345 G¿>¿C) of the COL4A1 gene is the first report of a non-syndromic, autosomal dominant congenital cataract, thereby highlighting the important role of type IV collagen in the physiological and optical properties of the lens.BMC Medical Genetics 08/2014; 15(1):97. · 2.45 Impact Factor
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ABSTRACT: Mutations in Peroxidasin (PXDN) cause severe inherited eye disorders in humans, such as congenital cataract, corneal opacity, and developmental glaucoma. The role of peroxidasin during eye development is poorly understood. Here we describe the first Pxdn mouse mutant which was induced by ENU (N-ethyl-N-nitrosourea) and led to a recessive phenotype. Sequence analysis of cDNA revealed a T3816A mutation resulting in a premature stop codon (Cys1272X) in the peroxidase domain. This mutation causes severe anterior segment dysgenesis and microphthalmia resembling the manifestations in patients with PXDN mutations. The proliferation and differentiation of the lens is disrupted in association with aberrant expression of transcription factor genes (Pax6 and Foxe3) in mutant eyes. Additionally, Pxdn is involved in the consolidation of the basement membrane and lens epithelium adhesion in the ocular lens. Lens material including γ-crystallin is extruded into the anterior and posterior chamber due to local loss of structural integrity of the lens capsule as a secondary damage to the anterior segment development leading to congenital ocular inflammation. Moreover, Pxdn mutants exhibited an early-onset glaucoma and progressive retinal dysgenesis. Transcriptome profiling revealed that peroxidasin affects the transcription of developmental and eye diseases-related genes at early eye development. These findings suggest that peroxidasin is necessary for cell proliferation and differentiation and for basement membrane consolidation during eye development. Our studies provide pathogenic mechanisms of PXDN mutation-induced congenital eye diseases.Human Molecular Genetics 06/2014; · 6.68 Impact Factor