The Cerebral Autosomal-Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL) Scale: a screening tool to select patients for NOTCH3 gene analysis.

BACKGROUND AND PURPOSE: Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) phenotype is highly variable, and, although the full clinical-neuroimaging picture may be suggestive of the disease, no characteristic is pathognomonic. Thus, a genetic test remains the diagnostic gold standard, but because it is costly and time-consuming, a pregenetic screening appears desirable. We aimed at developing the CADASIL scale, a screening tool to be applied in the clinical setting. METHODS: A preliminary scale was created assigning weighted scores to common disease features based on their frequencies obtained in a pooled analysis of selected international CADASIL series. The accuracy of the scale versus the genetic diagnosis was tested with receiver operating characteristic analysis after the application of this scale to 61 CADASIL and 54 NOTCH3-negative patients (no pathogenic mutation on exons 2-23 of the NOTCH3 gene). To improve the scale accuracy, we then developed an ad hoc optimization algorithm to detect the definitive scale. A third group of 39 patients affected by sporadic small-vessel disease was finally included in the algorithm to evaluate the stability of the scale. RESULTS: The cutoff score of the definitive CADASIL scale had a sensitivity of 96.7% and a specificity of 74.2%. This scale was robust to contamination of patients with sporadic small-vessel disease. CONCLUSIONS: The CADASIL scale is a simple and sufficiently accurate screening tool to select patients with a high probability to be affected by the disease and therefore to be subjected to the genetic testing.

Bone marrow-derived progenitor cells in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited disease due to cerebral microangiopathy presenting with variable pictures, including stroke, progressive cognitive impairment, and disability. Mechanisms leading from vessel structural changes to parenchymal damage and eventually to clinical expression are not fully understood. Among pathogenic processes, endothelial dysfunction has been hypothesized. Endothelial progenitor cells and circulating progenitor cells (CPCs) derived from bone marrow participate in endothelium structure and function maintenance and contribute to ischemic area revascularization. No data are available about these cells in CADASIL. Our objective in this study was to evaluate endothelial progenitor cells and CPCs role in CADASIL. METHODS: Twenty-nine patients with CADASIL and 29 sex- and age-matched control subjects were enrolled. Cells were measured in peripheral blood using flow cytometry. Endothelial progenitor cells were defined as positive for CD34/KDR, CD133/KDR, and CD34/CD133/KDR; and CPCs as positive for CD34, CD133, and CD34/CD133. RESULTS: Endothelial progenitor cells were significantly lower in patients with CADASIL than in control subjects (CD34/KDR: 0.05 versus 0.1 cells/microL, P=0.005; CD133/KDR: 0.07 versus 0.1 cells/microL, P=0.006; CD34/CD133/KDR: 0.05 versus 0.1 cells/microL, P=0.001). The difference remained significant after adjusting for age, sex, and statin use. CPCs were not significantly lower in CADASIL, but patients with stroke or dementia had significantly reduced CPC levels than patients without (CD34: 1.68 versus 2.95 cells/microL, P=0.007; CD133: 1.40 versus 2.82 cells/microL, P=0.004; CD34/CD133: 1.44 versus 2.75 cells/microL, P=0.004). CPC levels significantly correlated with cognitive and motor performance measures. CONCLUSIONS: We have documented an association between endothelial progenitor cells and CPCs and CADASIL, extending previous data about the presence of endothelial dysfunction in this disease and its potential role in modulating phenotype.

Right-to-left shunt in CADASIL patients: prevalence and correlation with clinical and MRI findings.

BACKGROUND AND PURPOSE: A high prevalence of right-to-left shunt (RLS) was described in a family of patients with CADASIL, a rare cerebral arteriopathy attributable to Notch3 gene mutations. The aim of this study was to determine the prevalence of RLS in patients with CADASIL and possible relation to clinical phenotype and cerebral MRI lesion load. METHODS: Twenty-three CADASIL patients underwent Transcranial Doppler with gaseous contrast to asses RLS. Correlations between RLS, clinical features, and MRI lesion volume (LV) were determined. RESULTS: Large RLS was diagnosed in 47% of patients. No significant clinical or MRI differences were found between patients with and without RLS. CONCLUSIONS: We found a high prevalence of RLS in our group of CADASIL patients. This may not be a coincidence, but can be rather related to the role of the Notch receptor family in the development of cardiovascular system.

Plasma levels of asymmetric dimethylarginine in cerebral autosomal dominant arteriopathy with subcortical infarct and leukoencephalopathy.

BACKGROUND: Asymmetric dimethylarginine (ADMA) is a marker of endothelial dysfunction and a new independent risk factor for adverse cerebrovascular events in small vessel disease. Conversely, L-arginine (LARG) may have a protective role. METHODS: To assess ADMA, LARG levels and LARG/ADMA ratio in 16 patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and normal controls, and to look for possible correlations with white matter changes. Plasma levels of ADMA and LARG were assayed by high-performance liquid chromatography in all subjects. The overall T(1) and T(2) lesion load was obtained from brain MRI of patients with CADASIL. RESULTS: ADMA plasma concentrations (1.5 +/- 2.0 microM) were significantly higher (p < 0.05) in CADASIL patients than in controls (0.35 +/- 0.075 microM). Analyzing only CADASIL subjects, an inverse borderline-significant correlation was found between LARG/ADMA (190 +/- 20) and T(2)-weighted lesion volumes (57.9 +/- 46.5; r = -0.578, p = 0.024). CONCLUSION: Our results may indicate the possible coexistence of endothelial dysfunction in CADASIL patients, broadening the range of potentially pathogenetic mechanisms in this disease and providing insights for future therapeutic strategies.

A novel heteroplasmic tRNA(Ser(UCN)) mtDNA point mutation associated with progressive external ophthalmoplegia and hearing loss.

We sequenced all mitochondrial tRNA genes from a patient with sporadic external ophthalmoplegia (PEO) and 5% COX-negative fibers in muscle biopsy, who had no detectable large mtDNA deletions. Direct sequencing showed a heteroplasmic mutation at nucleotide 7506 in the dihydrouridine stem of the tRNA(Ser(UCN)) gene. RFLP analysis confirmed that 30% of muscle and 20% of urinary epithelium mtDNA harbored the mutation, which was absent in other tissues of the proband as well as in mtDNA of his mother and 100 patients with various encephalomyopathies. Several point mutations on mitochondrial tRNA genes have been reported in PEO patients without large-scale rearrangements of mtDNA but no point mutations have hitherto been found in the gene coding for tRNA(Ser(UCN)).

Dysautonomic achalasia in two siblings with Sandhoff disease.

Two siblings in their sixth decade with chronic Type II GM2 gangliosidosis developed progressive dysphagia in addition to chronic motor neuron disease and autonomic nervous system (ANS) involvement. Esophageal achalasia was diagnosed in both patients. It is suggested that this esophageal motor disorder may be a manifestation of the neurovegetative system disorder due to alteration of ganglioside metabolism.

CADASIL in central Italy: a retrospective clinical and genetic study in 229 patients.

The objective of the study is to detail clinical and NOTCH3 gene mutational spectrum in a large group of Italian CADASIL patients. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a familial cerebral small vessels disease caused by mutations in the NOTCH3 gene on 19p13 usually presenting in young or middle adulthood. Characteristic features include migraine, recurrent lacunar stroke, subcortical dementia, mood disturbances and leukoencephalopathy. The disorder is often overlooked and misdiagnosed. CADASIL prevalence and disease burden is still undetermined. We retrospectively reviewed demographic, clinical, and mutational characteristic of all CADASIL patients diagnosed from January 2002 to December 2012 in three referral centers for neurogenetic and cerebrovascular diseases in central Italy. 229 NOTCH3 positive subjects were identified. Mean age at diagnosis was 57.8 ± 14.7 years, and 48.6 ± 17.1 years at first symptom onset. Most frequent clinical symptoms were ischemic events (59 %) and psychiatric disturbances (48 %). The highest percentage of mutations were found on exons 4 and 19 (20.6 and 17.6 % respectively), the remaining being dispersed over the entire EGF-like region of the NOTCH3 gene. 209 patients resided in a circumscribed geographic area which included three regions of the central Italy, yielding a minimum prevalence of 4.1 per 100.000 adult inhabitants. This is the most extensive study on CADASIL in Italy. Clinical phenotype showed several peculiarities in frequency and presentation of the main disease manifestations. Our study enlarges the number of pathogenic NOTCH3 mutations and due to the heterogeneous mutational spectrum observed suggests that full sequencing of exons 2-24 is mandatory for CADASIL screening in the Italian population.