Prevalence of Fabry disease and GLA variants in young patients with acute stroke: The challenge to widen the screening. The Fabry-Stroke Italian Registry.

BACKGROUND: Fabry disease (FD) is a treatable X-linked lysosomal storage disorder caused by GLA gene variants leading to alpha-galactosidase A deficiency. FD is a rare cause of stroke, and it is still controversial whether in stroke patients FD should be searched from the beginning or at the end of the diagnostic workup (in cryptogenic strokes). METHODS: Fabry-Stroke Italian Registry is a prospective, multicentric screening involving 33 stroke units. FD was sought by measuring α-galactosidase A activity (males) and by genetic tests (males with reduced enzyme activity and females) in patients aged 18-60 years hospitalized for TIA, ischemic stroke, or intracerebral hemorrhage. We diagnosed FD in patients with 1) already known pathogenic GLA variants; 2) novel GLA variants if additional clinical, laboratory, or family-derived criteria were present. RESULTS: Out of 1906 patients, we found a GLA variant in 15 (0.79%; 95%CI 0.44-1.29) with a certain FD diagnosis in 3 (0.16%; 95%CI 0.03-0.46) patients, none of whom had hemorrhage. We identified 1 novel pathogenic GLA variant. Ischemic stroke etiologies in carriers of GLA variants were: cardioaortic embolism (33%), small artery occlusion (27%), other causes (20%), and undetermined (20%). Mild severity, recurrence, previous TIA, acroparesthesias, hearing loss, and small artery occlusion were predictors of GLA variant. CONCLUSION: In this large multicenter cohort the frequency of FD and GLA variants was consistent with previous reports. Limiting the screening for GLA variants to patients with cryptogenic stroke may miss up to 80% of diagnoses. Some easily recognizable clinical features could help select patients for FD screening.

"CADASIL coma" in an Italian homozygous CADASIL patient: comparison with clinical and MRI findings in age-matched heterozygous patients with the same G528C NOTCH3 mutation.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic disorder caused by mutations in the NOTCH3 gene, with a striking variability in phenotypic expression. To date, only two homozygous patients have been reported, with divergent phenotypic features. We describe an Italian CADASIL patient, homozygous for G528C mutation, in whom early manifestation of the disease was migraine, but whose clinical evolution was characterized by a reversible acute encephalopathy followed by full recovery ("CADASIL coma"). Clinical evaluation, MR scan, neuropsychological and neurophysiological investigation did not reveal substantial differences between our homozygous patient and her heterozygous relatives sharing the same mutation, or between our patient and a group of heterozygous individuals with the same mutation but from different families. Skin biopsy identified peculiar features in the homozygous patient, with cytoplasmic pseudoinclusions likely containing granular osmiophilic material (GOM) in the vascular smooth muscle cells, but further studies are necessary to substantiate their possible relationships with CADASIL homozygosis. "CADASIL coma" did not seem to be specific of patient's homozygosis, since it was observed in one of her heterozygous relatives, whereas its pathogenesis seems to be related to peculiar constellations of unknown predisposing factors. The present study demonstrated that CADASIL conforms to the classical definition of dominant diseases, according to which homozygotes and heterozygotes for a defect are phenotypically indistinguishable.

Parkinsonism is a late, not rare, feature of CADASIL: a study on Italian patients carrying the R1006C mutation.

BACKGROUND AND PURPOSE: To describe parkinsonism as a clinical manifestation of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy. METHODS: We report 5 patients carrying the R1006C mutation in the exon 19 of NOTCH3 gene. All cases presented late onset, slowly progressive parkinsonism, not responsive to l-dopa. We performed brain MRI and (123)I-FP-CIT SPECT in all and in 3 additional patients carrying the same mutation but without parkinsonism. Four patients with parkinsonism underwent myocardial (123)I-meta-iodobenzylguanidine scintigraphy. RESULTS: In all patients, brain MRI showed widespread ischemic lesions in the periventricular white matter, the internal and external capsules, the basal ganglia, and thalami. (123)I-FP-CIT SPECT showed symmetrical or asymmetrical reduction of tracer uptake in the putamen, with inconstant caudate involvement. Myocardial (123)I-meta-iodobenzylguanidine scintigraphy resulted normal. Nigrostriatal denervation was also demonstrated in 2 patients without parkinsonism. CONCLUSIONS: In cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, parkinsonism may be a not rare, late onset manifestation. The clinical picture, the lack of response to dopaminergic treatment, and MRI findings suggest a vascular parkinsonism, which may be preceded by a protracted presymptomatic phase.

Multi-organ investigation in 16 CADASIL families from central Italy sharing the same R1006C mutation.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) may involve many target organs with relevant variability among affected individuals. We performed a multi-organ assessment tapping nervous system, skeletal muscle and cardiovascular system in thirty-nine individuals belonging to 16 families from Central Italy sharing the same R1006C CADASIL mutation. Stroke prevalence was larger in female patients (66.7%) than in males (23.8%); high levels of CKemia were quite frequent (21.6%) and were related to a myopathy without mitochondrial alterations; several individuals had atrial septal aneurysm (10.3%). No specific relationships between common cardiovascular risk factors and clinical manifestations were found. The present systematic study thus identified several gender-related, myopathic and cardiovascular peculiarities of R1006C mutation. This kind of comprehensive approach is necessary to define clinical course, prognosis and treatment options for a multi-organ disease such as CADASIL.

Shorter telomeres in patients with cerebral autosomal dominant arteriopathy and leukoencephalopathy (CADASIL).

CADASIL is a hereditary systemic vasculopathy which affects mainly small cerebral arteries and is caused by mutations in the Notch3 gene. Misfolding of Notch3 is linked to endoplasmic reticulum stress and increased reactive oxygen species, which may result in dysfunction of endothelial cells, inflammation and ischemia. Oxidative stress and inflammation may induce a rapid telomere shortening in peripheral blood leukocytes (PBLs). The aim of this study was to assess the telomere length in PBLs from 29 patients with a genetic diagnosis of CADASIL by using a modified quantitative real-time polymerase chain reaction based assay. PBL telomere length was significantly shorter in CADASIL patients (T/S ratio = 0.17, 95% CI, 0.14-0.20) than in the controls (T/S ratio = 0.31, 95% CI, 0.27-0.35, t-test p < 0.001). Moreover, patients with functional dependence displayed shorter telomeres than those with functional independence (p = 0.039). Our data provide the first evidence that PBL telomere length is shortened in CADASIL disease, and this may be a systemic oxidative stress indicator in CADASIL patients, providing a possible biomarker of disease progression and for future therapeutic strategies.