Biomedical subjects

Alessandro Malandrini

Publications and source records attributed to Alessandro Malandrini.

9 recordsLinked to original sources

PubMed2006

Spastic paraplegia with thin corpus callosum: description of 20 new families, refinement of the SPG11 locus, candidate gene analysis and evidence of genetic heterogeneity.

We studied 20 Mediterranean families (40 patients) with autosomal recessive hereditary spastic paraplegia and thin corpus callosum (ARHSP-TCC, MIM 604360) to characterize their clinical and genetic features. In six families (17 patients) of Algerian Italian, Moroccan, and Portuguese ancestry, we found data consistent with linkage to the SPG11 locus on chromosome 15q13-15, whereas, in four families (nine patients of Italian, French, and Portuguese ancestry) linkage to the SPG11 locus could firmly be excluded, reinforcing the notion that ARHSP-TCC is genetically heterogeneous. Patients from linked and unlinked families could not be distinguished on the basis of clinical features alone. In SPG11-linked kindred, haplotype reconstruction allowed significant refinement to 6 cM, of the minimal chromosomal interval, but analysis of two genes (MAP1A and SEMA6D) in this region did not identify causative mutations. Our findings suggest that ARHSP-TCC is the most frequent form of ARHSP in Mediterranean countries and that it is particularly frequent in Italy.

Adolescent↗

PubMed2006

A new missense mutation in caveolin-3 gene causes rippling muscle disease.

Mutations of the Cav-3 gene are associated with distinct, sometimes overlapping muscle disease phenotypes. We report a new Italian family with autosomal dominant rippling muscle disease. Immunocytochemical analysis of muscle showed a deficit of caveolin-3 protein and molecular genetic analysis showed a novel mutation of the Cav-3 gene.

Adult↗

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

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

Autosomal dominant hereditary spastic paraplegia: DHPLC-based mutation analysis of SPG4 reveals eleven novel mutations.

We set up a new denaturing high-performance liquid chromatography (DHPLC)-based protocol to screen patients with autosomal dominant hereditary spastic paraplegia (AD-HSP) for mutations in SPG4. Six patients had a complicated form and 49 a pure HSP phenotype. We also analyzed 19 unrelated patients presenting with an HSP phenotype (pure in 17 and complicated in two subjects) but no clear family history, as such patients may be cases of dominant inheritance with low penetrance. The overall frequency of SPG4 mutations in our study of HSP (in which prior linkage data were unavailable) was 32.4%, rising to 46.9% when only pure AD-HSP patients were considered. This figure falls well within the range reported in different populations. Rather as expected, the clinical data available for the patients did not support an easy genotype-phenotype correlation. Moreover, the clinical picture was not influenced by the length of the predicted residual gene product. As well as identifying novel variants in SPG4, this study constitutes the molecular characterization of the largest cohort of Italian AD-HSP patients studied to date. In addition, it provided an efficient, cost-effective, and reliable detection protocol for mutational screening of SPG4, which might facilitate medical genetic counseling.

Adenosine Triphosphatases↗

PubMed2004

Antibodies to dorsal root ganglia and olfactory cells in a patient with chronic sensory neuropathy and anosmia.

We report the case of a 51-year-old woman with anosmia and chronic sensory ataxic neuropathy. Olfactory tests suggested neurosensory anosmia. Immunocytochemical analysis showed serum antibodies against dorsal root ganglion (DRG) cells and olfactory neurons, in the absence of other known causes of anosmia and sensory neuropathy. Clinical and laboratory data suggested a slow autoimmune process affecting dorsal root ganglion and olfactory cells.

Antibodies↗

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↗

PubMed2003

Nerve growth factor expression in human dystrophic muscles.

Nerve growth factor (NGF) is a neurotrophin that is expressed during muscle development and is also capable of favoring muscle regeneration in experimental studies. The presence of NGF in muscular dystrophies, such as Duchenne and Becker muscular dystrophies, has never been fully explored. By means of immunohistochemistry, we show that regenerating muscle fibers from such patients consistently express NGF, as do myofibroblasts and mast cells. By contrast, rest fibers from dystrophic patients, as well as muscle fibers from healthy, control patients and even regenerative muscle fibers in polymyositis do not show NGF immunoreactivity. The paracrine effect of NGF on muscle regeneration, as well as its chemoattractant capacities for mast cells, may contribute to explaining why regenerating fibers most frequently occur in clusters and why mast cells are more numerous in dystrophic muscles. Moreover, being a mediator of wound healing and tissue fibrosis, NGF may contribute to long-term muscle regeneration impairment by tissue fibrosis in the muscular dystrophies.

Biopsy↗

PubMedDate not supplied

Early diagnosis in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL): the role of MRI.

The aim of our work was to evaluate the early presence of white matter changes on magnetic resonance imaging (MRI) in young asymptomatic children of patients with full-blown cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in whom DNA analysis revealed a Notch3 Cys146Tyr missense mutation on chromosome 19. Brain MRI was performed in all subjects using axial and coronal spin-echo proton density and T2-weighted images, axial fluid-attenuated inversion recovery (FLAIR) and sagittal and axial T1-weighted images. In asymptomatic subjects with Notch3 gene mutation, MRI showed small T2 hyperintense foci in periventricular and subcortical white matter. Routine use of MRI in the initial phases of a CADASIL diagnostic work up and the subsequent recognition of early abnormal findings in asymptomatic subjects may lead to prompt diagnosis of the disease in these patients. Moreover, these findings suggest that genetic screening is warranted in the presence of a suspect clinical history with specific MRI abnormalities.

Adult↗