The present case illustrates the clinicopathological spectrum of COL4A1-related cerebral SVD presenting as hemorrhagic stroke in the young with porencephaly, intellectual disability, and Axenfield-Rieger anomaly and thus adds to the clinical heterogeneity of this genetic disorder.
Recently, germline mutations in collagen type IV alpha 1 (COL4A1) have been reported to be a genetic cause of schizencephaly as a result of prenatal stroke.
We identified an exonic polymorphism in NOS3 (rs1799983, rs1799983" genes_norm="4846">p.Glu298Asp; p = 2.2E-8, odds ratio [OR] = 1.05, 95% confidence interval [CI] = 1.04-1.07) and variants in an intron of COL4A1 (rs9521634; p = 3.8E-8, OR = 1.04, 95% CI = 1.03-1.06) and near DYRK1A (rs720470; p = 6.1E-9, OR = 1.05, 95% CI = 1.03-1.07) at genome-wide significance for stroke.
COL4A1-associated disorders encompass a wide range of hereditary vasculopathy, including porencephaly and HANAC (adult-onset hemorrhagic stroke with cerebral aneurysm and retinal arterial tortuosity, renal cysts, and thenar muscle cramp).
This article reviews the existing literature on the most investigated monogenic disorders (CADASIL, Fabry disease, MELAS, RVCL, COL4A1, Marfan and Ehlers-Danlos syndromes) causing stroke in young and a number of candidate genes associated with stroke occurring in patients younger than 50 years.
In the present review article we will focus on the molecular basis of the COL4A1stroke syndrome, summarize data on its variable phenotype, and explore additional questions concerning the possible genotype-phenotype correlations and the mechanisms leading to cerebral small-vessel disease in this clinically heterogeneous condition.
Ehler-Danlos type IV), disorders of cerebral small vessels (e.g. cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy and the collagen COL4A1 mutation), disorders increasing the thrombogenic potential of the heart through affecting the myocardium or the heart valves or through disturbance of the heart rhythm (e.g. hypertrophic cardiomyopathy), mitochondrial cytopathies increasing cerebral tissue susceptibility to insults (e.g. mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes), and finally disorders of coagulation that can either directly cause stroke or act synergistically with the aforementioned abnormalities (e.g. sickle cell disease).