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Maria Teresa Dotti

Publications and source records attributed to Maria Teresa Dotti.

16 recordsLinked to original sources
PubMed2006

Physiology and pathology of notch signalling system.

Notch proteins encode a family of transmembrane receptors that are part of a signalling transduction system known as Notch signalling, an extremely conserved and widely used mechanism regulating programs governing growth, apoptosis and differentiation in metazoans. Notch signalling begins when the Notch receptor binds ligands and ends when the Notch intracellular domain enters the nucleus and activates transcription of target genes. This core pathway is subjected to a wide array of regulatory influences and protein-protein interactions and is correlated with other signalling pathway. This review will summarize recent findings concerning the physiology and pathology of Notch signalling in vascular development and homeostasis. Moreover, the clinical phenotypes of Notch3 signalling system pathology will be described, with particular regard to CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy) for which the most recent pathogenetic hypotheses are reported.

Animals↗
PubMed2005

Rapidly progressive neurodegeneration in a case with the 7472insC mutation and the A7472C polymorphism in the mtDNA tRNA ser(UCN) gene.

The authors report the clinical, neuroimaging, muscle biopsy and mtDNA findings in a patient affected by bilateral hearing loss and mental retardation since infancy, presenting at age 31 years with a rapid deterioration of mental status and ataxia leading to vegetative condition and death at the age of 32 years. Clinical and genetic studies have been also performed in the mother, affected by neurosensorial hearing loss. Muscle biopsy showed severe mitochondrial alterations in the propositus and evidence of mitochondrial alterations in his mother. Direct mtDNA sequencing in all family members revealed the known 7472insC mutation and the recently described A7472C sequence variation in the tRNA(Ser(UCN))gene. RFLP-PCR confirmed the heteroplasmic nature of the two mutations and failed to find the second transversion in 200 controls. The percentage of mutant genomes harbouring 7472insC ranged from 3 to 7% in asymptomatic family members to 70% in the proband and his mother, whereas the percentage of A7472C mutant genomes was about 90% in all maternal relatives except the proband (56%) and his sister (5%). In conclusion, this is the first report of a rapidly progressive encephalopathy in association with the 7472insC mutation in mtDNA, combined with an A>C variation at the same nucleotide with a possible suppression effect on the pathogenic mutation.

Adult↗
PubMed2005

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.

Autonomic Nervous System Diseases↗
PubMed2005

Systemic blood pressure profile in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic form of subcortical ischemic vascular dementia (SIVD). The most common vascular risk factors are unremarkable in CADASIL; however, studies on systemic blood pressure (BP) changes over time are substantially lacking. Because BP instability is a relevant risk factor for developing or worsening white matter changes in sporadic SIVD, we aimed to study the BP profile of CADASIL to investigate its relationship with cognitive decline and white matter injury. METHODS: Twenty-four-hour ambulatory BP monitoring was performed in a group of 14 CADASIL patients (12 males and 2 females) and in a group of 15 healthy age-matched control subjects. The following BP variables were compared between the 2 groups: mean daytime and nighttime systolic, diastolic, and mean arterial BP (SABPday, DABPday, and MABPday, and SABPnight, DABPnight, and MABPnight) and nocturnal percentage decline in arterial BP (%MABP reduction). Cognitive performances were tested by mini mental status examination (MMSE), and brain MRI was performed to extrapolate the T2-weighted lesion volume (LV) in each CADASIL patient. The 24-hour arterial BP variables were compared between CADASIL and controls. In addition, for CADASIL patients only, MMSE, LV, and age were compared with each pressure variable. RESULTS: Patients with CADASIL showed a significant reduction (P<0.05) of SABPday, DABPday, MABPday and %MABP decline with respect to controls. In addition, MMSE of CADASIL subjects correlated significantly (P<0.0001) with daytime MABP. CONCLUSIONS: The low systemic BP profile observed in CADASIL patients was specifically attributable to reduced diurnal BP values. This may further affect cerebral hemodynamics and increase the risk of cognitive impairment in these patients. The pathogenesis of abnormal BP profile in CADASIL remains to be clarified. It is likely that central and peripheral mechanisms controlling BP variations are involved.

Adolescent↗
PubMed2005

Peripheral neuropathy in CADASIL.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is a hereditary cerebral microangiopathy associated with mutations in the Notch 3 gene. The clinical phenotype is characterized by cerebral impairment even though typical microvascular changes are diffuse. OBJECTIVE: To assess peripheral neuropathy in patients with CADASIL. PATIENTS AND METHODS: We enrolled eleven CADASIL patients with variable phenotype including clinical signs of peripheral nerve involvement. In all patients electromyography and nerve conduction velocities were performed. Peripheral nerve biopsy was performed in three cases. RESULTS: We found sensory motor neuropathy in 7/11 patients. Nerve biopsy revealed axonal and demyelinated findings. CONCLUSION: Our findings suggest that peripheral neuropathy may be part of the CADASIL phenotype.

Action Potentials↗
PubMed2005

A novel heteroplasmic tRNA(Leu(CUN)) mtDNA point mutation associated with chronic progressive external ophthalmoplegia.

We have sequenced all mitochondrial tRNA genes from a patient with chronic progressive external ophthalmoplegia (CPEO) and mitochondrial myopathy, who had no detectable large mtDNA deletions. Direct sequencing failed to detect previously reported mutations and showed a heteroplasmic mutation at nucleotide 12,276 in the tRNA(Leu(CUN)) gene, in the dihydrouridine stem, which is highly conserved through the species during evolution. RFLP analyses confirmed that 18% of muscle mtDNA harbored the mutation, while it was absent from DNA of fibroblasts and lymphocytes of the proband and in 110 patients with other encephalomyopathies. To date, besides large and single nucleotide deletions, several point mutations on mitochondrial tRNA genes have been reported in CPEO patients, but only three were in the gene coding for tRNA(Leu(CUN)).

Animals↗
PubMed2005

Leber hereditary optic neuropathy in 2 of 4 siblings with 11778 mtDNA mutation: clinical variability or effect of toxic environmental exposure?

Although mitochondrial (mt) DNA mutation at nucleotide position 11778 accounts for most cases of Leber's hereditary optic neuropathy (LHON), the phenotypic expression may vary greatly even in different members of the same family. The possible influence of exogenous toxicity on phenotypic expression is still debated in LHON. Here we describe 4 siblings carrying the 11778 mtDNA mutation with a different phenotype. The index case developed an atypical optic neuropathy at the age of 60 years after a long history of occupational exposure to polycyclic aromatic hydrocarbons (PAHs). This report underlines a number of unanswered questions about phenotypic variability of LHON including the possible influence of PAH toxicity.

Aged↗
PubMed2004

Acute unilateral visual loss as the first symptom of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND: Although cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is considered a cerebrovascular disorder with almost exclusively neurological symptoms, the arteriopathy is generalized and involves choroidal and retinal vasculature as demonstrated by fluorescein angiographic and ocular electrophysiological abnormalities. The occurrence of acute visual loss due to nonarteritic anterior ischemic optic neuropathy (NAION) has not previously been reported in CADASIL. OBJECTIVE: To describe acute visual loss due to NAION as a possible manifestation of CADASIL. PATIENTS AND METHODS: The patient was a 60-year-old man with subcortical diffuse leukoencephalopathy, multi-infarct dementia, tetraparesis, visual loss, and a family history of stroke. We performed clinical and neuro-ophthalmological evaluation, electrophysiological assessment, brain magnetic resonance imaging, and genetic screening for mutations or small deletions of the Notch3 gene, (causing CADASIL). RESULTS: The patient's first symptom was acute visual loss in the right eye due to NAION at age 27 years, in absence of the common cardiovascular risk factors and before any neurological impairment. The patient was reevaluated at age 60 years, and neuro-ophthalmological examination showed optic disc atrophy in the right eye with arteriolar narrowing and a reduction in visual acuity in the left eye. Fluorescein angiography of the right eye showed evidence of persistent peripapillary hypofluorescence with a retinal pigment epithelial windows defect in the inferior temporal area. Pattern reversal visual evoked potentials were abolished in the right eye. The P100 latency of the left eye was delayed and reduced in amplitude. The diagnosis of CADASIL was confirmed by molecular analysis (heterozygotes for the C406T mutation on exon 3 of the Notch3 gene). There was a family history of cerebrovascular disorders and ocular impairment. CONCLUSIONS: Visual loss due to transient or stable ischemic events involving the optic nerve head should be considered in the CADASIL phenotype. The possibility of CADASIL should also be evaluated in patients with NAION who do not have cardiovascular risk factors but do have a family history of stroke.

Blindness↗
PubMed2004

A novel NOTCH3 frameshift deletion and mitochondrial abnormalities in a patient with CADASIL.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), which leads to strokes and dementia, is caused by single missense mutations or, in a few cases, small deletions in the NOTCH3 gene. These mutations result in a gain or a loss of 1 (or, rarely, 3) cysteine residue in 1 of 34 epidermal growth factor-like repeats in the extracellular amino-terminal region of NOTCH3. OBJECTIVE: To describe a patient with a novel NOTCH3 mutation in whom clinical and laboratory findings of mitochondrial abnormalities were associated with a diagnosis of CADASIL. Patient A patient with a history of migraines, repeated transient ischemic attacks, and generalized fatigue underwent muscle biopsy, brain magnetic resonance spectroscopic imaging, and screening of mitochondrial DNA and NOTCH3. RESULTS: Molecular genetic analysis showed a NOTCH3 mutation (the first documented frameshift deletion in a patient with CADASIL) in exon 4. Although the screening of mitochondrial DNA did not show mitochondrial mutations, findings from muscle biopsy and brain magnetic resonance spectroscopic imaging showed signs of mitochondrial impairment (ultrastructural mitochondrial abnormalities and increased parenchymal brain lactate, respectively). CONCLUSIONS: A patient with CADASIL and a 5-base pair deletion leading to a frameshift mutation showed clinical and laboratory evidence of mitochondrial dysfunction. This adds to the previously reported hypothesis of a pathogenetic role of NOTCH3 or, less specifically, a microvascular pathologic effect on mitochondrial energy metabolism.

Base Sequence↗
PubMed2004

Hemodynamic evaluation of the optic nerve head in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND: Although cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is considered a cerebrovascular disorder with almost exclusively neurological symptoms, arteriopathy is generalized and also involves the choroid and retina. OBJECTIVE: To study optic nerve head microvascular function in CADASIL by assessing blood flow, volume, and velocity with a retina flowmeter. PATIENTS AND METHODS: Scanning laser Doppler flowmetry permits the noninvasive assessment of relative blood velocity, volume, and flow in a sample volume of either retina or anterior optic nerve head. Measurements were performed in a first group of 9 eyes of 5 patients with CADASIL and a second group of 8 eyes of 4 healthy subjects. Hemodynamic parameters were computed in 4 quadrants of the optic disc (superior nasal, superior temporal, inferior nasal, and inferior temporal). The Wilcoxon rank sum test was used to assess differences in relative flow, volume, and velocity in each quadrant and between the 2 groups and differences in overall optic nerve head blood flow, volume, and velocity. RESULTS: Patients with CADASIL had a significant decrease in overall blood flow and volume compared with healthy subjects (P<.05). The reduction in blood flow and volume was particularly significant in the superior and inferior temporal quadrants. No significant differences were found nasally between the patients and the control groups. CONCLUSION: Our results suggest that hemodynamic parameters are abnormal in the superficial nerve fiber layer of the optic nerve head of patients with CADASIL, especially in the temporal quadrants of the neuroretinal rim.

Adult↗
PubMed2004

Chorein detection for the diagnosis of chorea-acanthocytosis.

Chorea-acanthocytosis (ChAc) is a severe, neurodegenerative disorder that shares clinical features with Huntington's disease and McLeod syndrome. It is caused by mutations in VPS13A, which encodes a large protein called chorein. Using antichorein antisera, we found expression of chorein in all human cells analyzed. However, chorein expression was absent or noticeably reduced in ChAc patient cells, but not McLeod syndrome and Huntington's disease cells. This suggests that loss of chorein expression is a diagnostic feature of ChAc.

Acanthocytes↗
PubMed2004

Autonomic dysfunction in mental retardation and spastic paraparesis with MECP2 mutation.

Autonomic nervous system involvement in female patients with classic Rett syndrome usually manifests as breathing abnormalities, peripheral vasomotor disturbances, and cardiac sympathetic imbalance, the latter a possible cause of sudden death. MECP2 gene mutations responsible for Rett syndrome have also been found in male patients with mental retardation, sometimes associated with different neurologic abnormalities. However, autonomic nervous system functions have never been investigated in male patients with X-linked mental retardation owing to MECP2 mutations. We studied heart rate variability, a marker of autonomic activity, in a family with the MECP2 mutation in male patients, one of whom had died suddenly. Cardiovascular features similar to those observed in a Rett syndrome variant with preserved speech were found, suggesting sympathetic imbalance.

Adult↗
PubMed2003

Adult onset Niemann-Pick type C disease: A clinical, neuroimaging and molecular genetic study.

We report on a patient with adult-onset Niemann-Pick type C (NPC) disease, carrying the mutations P1007 and I1061T in the NPC1 gene, presenting with marked psychiatric changes followed by dystonia and cognitive impairment. Filipin staining, single photon emission computed tomography perfusional, positron emission tomography metabolic, conventional magnetic resonance imaging, and magnetic resonance spectroscopy findings suggested a pathophysiological correlation with phenotype expression. This case expands the clinical and genetic spectrum of the rare adult-onset NPC disease phenotype.

Adult↗