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Biomedical subjects

M T Dotti

Publications and source records attributed to M T Dotti.

At least 19 recordsLinked to original sources

Auditory neuropathy in a patient with mitochondrial myopathy and multiple mtDNA deletions.

Auditory neuropathy (AN) is a hearing disorder characterized by the absence or severe distortion of the auditory brainstem responses, in the presence of preserved otoacoustic emissions. This peculiar combination suggests the presence of a defect impinging upon the functional complex formed by inner hair cells, the primary afferents (spiral ganglion neurones) and the first order synapses between hair cells and the cochlear nerve. Typically, AN patients show a severe speech perception impairment, which appears reduced out of proportion to pure tone threshold, but the clinical presentation of AN is quite complex. Hearing loss is a common symptom associated with mitochondrial diseases; however, AN has only rarely been reported in these disorders. Here we report a rare association, the first case observed in Italy, in a patient with autosomal recessive mitochondrial myopathy and mitochondrial DNA multiple deletions, and a hearing deficit with the audiological and electrophysiological features of AN.

DNA, Mitochondrial↗

Clinical and molecular diagnosis of cerebrotendinous xanthomatosis with a review of the mutations in the CYP27A1 gene.

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disease due to defective activity of the mitochondrial enzyme sterol 27-hydroxylase. In 1991, sterol 27-hydroxylase gene (CYP27A1) was localised on the long arm of chromosome 2 [1]. Clinical characteristics of CTX are diarrhoea, cataracts, tendon xanthomas and neurological manifestations including dementia, psychiatric disturbances, pyramidal and/or cerebellar signs, and seizures. More than 300 patients with CTX have been reported to date worldwide and about 50 different mutations identified in the CYP27A1 gene. Almost all mutations lead to the absence or inactive form of the sterol 27-hydroxylase. In this review, according with the aims of this section of the journal, we describe the different pathogenetic mutations in the CYP27A1 gene and the main clinical and pathogenetic aspects that may help clinical neurologists in the diagnosis of CTX.

Cholestanetriol 26-Monooxygenase↗

Cerebellar arteriovenous malformation and vertebral artery aneurysm in a CADASIL patient.

The presence of large vessels malformations has not been reported in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). We describe a CADASIL patient in whom a brain cerebellar arteriovenous malformation was revealed by magnetic resonance (MR) imaging. An MR angiogram documented also an aneurysm along the right intracranial vertebral artery at the junction with the posterior-inferior cerebellar artery. The aneurysm was successfully treated by means of endovascular coil embolization. No neurological complication occurred in our patient during the angiographic procedure. In this case, in addition to an incidental coexistence of CADASIL and large vessels abnormalities, a causal role of the Notch pathway alteration could be hypothesized. Dysregulation of the Notch pathway is linked to several human diseases besides CADASIL. In one of these (the Alagille syndrome) intracranial aneurysms are reported. This hypothesis contrasts however with the absence of similar reports in other CADASIL cases and needs corroboration in large series.

Adult↗

The spectrum of mutations for CADASIL diagnosis.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is an inherited cerebrovascular disease due to mutations of the Notch3 gene at the chromosome locus 19p13. The clinical spectrum includes recurrent ischaemic episodes, cognitive deficits, migraine and psychiatric disorders. The histopathological hallmark of CADASIL is accumulation of electron dense granules (GOM) in the media of arterioles. MRI reveals extensive cerebral white matter lesions and subcortical infarcts. CADASIL was initially thought to be a rare disorder, but increasing numbers of families have been identified; therefore, it is likely that CADASIL is still largely underdiagnosed. Here we report an update on mutations of the Notch3 gene and some information on the pathogenesis of the disease.

Brain↗

Lung involvement in Niemann-Pick disease type C1: improvement with bronchoalveolar lavage.

Progressive lung infiltration is a major cause of death in Niemann-Pick disease type A and B (NPA, NPB) and in the recently defined type C2. In type C1 (NPC1), the main manifestations are neurological. We report a patient with a classic, neurological, late infantile form of NPC1 disease, carrying the mutation P474L and the variant I642M in the NPC1 gene, who suffered recurrent respiratory manifestations. Bronchoalveolar lavage of a lung segment due to deteriorating respiratory condition revealed many foamy macrophages and was followed by an improvement in symptoms. Pneumopathy may therefore be considered a feature of NPC1 disease for which a partial bronchoalveolar lavage could be a useful treatment.

Adolescent↗

Typical pathological changes of CADASIL in the optic nerve.

Visual impairment due to retinal and optic nerve changes in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is more common than previously thought. Deposits of granular osmiophilic material (GOM) have been shown in the wall of retinal arterioles, though retinal infarcts and vascular occlusions have never been reported. Ischaemic optic neuropathy, on the other hand, has been reported in one case of CADASIL but no pathology reports of the optic nerve have been published. Here we report optic nerve morphological findings in the autopsy material of a 41-year-old woman with genetically assessed CADASIL. Longitudinal and transverse sections of optic nerves were examined. Classical histological methods (haematoxylin-eosin and Nissl) were performed. Diffuse pallor of myelin and rarefaction of optic nerve fibres were observed. Classical GOM was evident in the tunica media of vessels in the meninges and white matter. Arteriole lumina were slightly narrowed. In conclusion, the typical pathological changes of CADASIL occur in the optic nerve and may contribute to impairment of visual function in CADASIL.

Adult↗

The spectrum of Notch3 mutations in 28 Italian CADASIL families.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is a cause of hereditary cerebrovascular disease. It results from mutations in the Notch3 gene, a large gene with 33 exons. A cluster of mutations around exons 3 and 4 was originally reported and limited scanning of these exons was suggested for the diagnosis in most cases. OBJECTIVE: To report Notch3 mutation analysis in 28 unrelated Italian CADASIL families from central and south Italy. RESULTS: The highest rate of mutations was found in exon 11 (21%) and only 18% of mutations were in exon 4. This may be related to the peculiar distribution of Notch3 mutations in the regions of origin of the families. CONCLUSIONS: The results suggest that limited scanning of exons 3 and 4 is inadvisable in CADASIL cases of Italian origin.

CADASIL↗

Clinical and molecular findings in patients with giant axonal neuropathy (GAN).

Giant axonal neuropathy (GAN) is a rare autosomal recessive neurodegenerative disorder of early onset, clinically characterized by a progressive involvement of both peripheral and CNS. The diagnosis is based on the presence of characteristic giant axons, filled with neurofilaments, on nerve biopsy. Recently, the defective protein, gigaxonin, has been identified and different pathogenic mutations in the gigaxonin gene have been reported as the underlying genetic defect. Gigaxonin, a member of the BTB/kelch superfamily proteins, seems to play a crucial role in the cross talk between the intermediate filaments and the membrane network. The authors report clinical and molecular findings in five Italian patients with GAN. This study shows the allelic heterogeneity of GAN and expands the spectrum of mutations in the GAN gene. The frequent occurrence of private mutations stresses the importance of a complete gene analysis.

Adolescent↗