The prenatal diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) by mutation analysis

High Prevalence of Collagenopathies in Preterm- and Term-Born Children With Periventricular Venous Hemorrhagic Infarction

INTRODUCTION

The aim of this study was to evaluate genetic risk factors in term-born children with antenatal periventricular hemorrhagic infarction (PVHI), presumed antenatal periventricular venous infarction and periventricular hemorrhagic infarction in preterm neonates.

METHODS

Genetic analysis and magnetic resonance imaging were performed in 85 children: term-born children (≥36 gestational weeks) with antenatal periventricular hemorrhagic infarction (n = 6) or presumed antenatal (n = 40) periventricular venous infarction and preterm children (<36 gestational weeks) with periventricular hemorrhagic infarction (n = 39). Genetic testing was performed using exome or large gene panel (n = 6700 genes) sequencing.

RESULTS

Pathogenic variants associated with stroke were found in 11 of 85 (12.9%) children with periventricular hemorrhagic infarction/periventricular venous infarction. Among the pathogenic variants, COL4A1/A2 and COL5A1 variants were found in 7 of 11 (63%) children. Additionally, 2 children had pathogenic variants associated with coagulopathy, whereas 2 other children had other variants associated with stroke. Children with collagenopathies had significantly more often bilateral multifocal stroke with severe white matter loss and diffuse hyperintensities in the white matter, moderate to severe hydrocephalus, moderate to severe decrease in size of the ipsilesional basal ganglia and thalamus compared to children with periventricular hemorrhagic infarction/periventricular venous infarction without genetic changes in the studied genes (P ≤ .01). Severe motor deficit and epilepsy developed more often in children with collagenopathies compared to children without genetic variants (P = .0013, odds ratio [OR] = 233, 95% confidence interval [CI]: 2.8-531; and P = .025, OR = 7.3, 95% CI: 1.3-41, respectively).

CONCLUSIONS

Children with periventricular hemorrhagic infarction/periventricular venous infarction have high prevalence of pathogenic variants in collagene genes (COL4A1/A2 and COL5A1). Genetic testing should be considered for all children with periventricular hemorrhagic infarction/periventricular venous infarction; COL4A1/A2 and COL5A1/A2 genes should be investigated first.

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) as a model of small vessel disease: update on clinical, diagnostic, and management aspects

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common and best known monogenic small vessel disease. Here, we review the clinical, neuroimaging, neuropathological, genetic, and therapeutic aspects based on the most relevant articles published between 1994 and 2016 and on the personal experience of the authors, all directly involved in CADASIL research and care. We conclude with some suggestions that may help in the clinical practice and management of these patients.

CADASIL: pathogenesis, clinical and radiological findings and treatment

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common genetic cause of ischemic strokes and a most important model for the study of subcortical vascular dementia. This unrelentlessly progressive disease affects many hundreds of families all over the world but is not well studied in Brazil. This manuscript reviews pathogenetic, clinical, radiological and therapeutic features of CADASIL. The causal mutations are now very well known, but the same can not be said about its intimate pathogenetic mechanisms. The variable clinical presentation should lead physicians to actively pursue the diagnosis in many settings and to more thouroughly investigate family history in first degree relatives. A rational approach to genetic testing is however needed. Treatment of CADASIL is still largely empiric. High-quality therapeutic studies involving medications and cognitive interventions are strongly needed in CADASIL.

CADASIL management or what to do when there is little one can do

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a rare disease that leads to migraine, mood disorders, recurrent lacunar strokes and early vascular dementia. This autosomal-dominant condition is caused by mutations in the NOTCH3 gene and is characterized by degeneration of vascular smooth muscle cells. At present, no evidence-based treatment for CADASIL is available and only relief of symptoms can be offered to patients. This review focuses on an update of CADASIL management, based on the recent clinical and basic evidence, and discusses possible new treatment targets for CADASIL.

Pregnancy following preimplantation genetic diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

OBJECTIVE

Presentation of a novel case, involving the design and implementation of preimplantation genetic diagnosis (PGD) for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

METHODS

The disease-causing mutation, c.459C>T (R153C) in exon 4 of the Notch3 gene, was previously identified in the affected father. The family already had a pregnancy termination following prenatal diagnosis and chose to undergo PGD. A PGD protocol was designed to include informative, linked short tandem repeat (STR) markers and an intragenic single nucleotide polymorphism (SNP), coupled to mutation identification. Biopsy was performed at day 3 and blastocysts were transferred on day 5 after fertilization. Standard prenatal diagnosis procedures were employed to confirm the PGD results.

RESULTS

One blastomere was removed at day 3 from each of eight embryos. Detection of the c.459C>TNotch3 mutation, coupled to informative polymorphic markers, unambiguously identified three unaffected embryos. Blastocyst transfer resulted in a singleton pregnancy and subsequent prenatal diagnosis confirmed that the fetus was disease-free.

CONCLUSIONS

Given the dominant, highly penetrant and potentially serious effects of Notch3 mutations, PGD for CADASIL may be considered and implemented as a reproductive option, following proper genetic counseling.