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Biomedical subjects

M T Dotti

Publications and source records attributed to M T Dotti.

At least 55 records · Page 3Linked to original sources
PubMed2000

MECP2 mutation in male patients with non-specific X-linked mental retardation.

In contrast to the preponderance of affected males in families with X-linked mental retardation, Rett syndrome (RTT) is a neurological disorder occurring almost exclusively in females. The near complete absence of affected males in RTT families has been explained by the lethal effect of an X-linked gene mutation in hemizygous affected males. We report here on a novel mutation (A140V) in the MECP2 gene detected in one female with mild mental retardation. In a family study, the A140V mutation was found to segregate in the affected daughter and in four adult sons with severe mental retardation. These results indicate that MECP2 mutations are not necessarily lethal in males and that they can be causative of non-specific X-linked mental retardation.

Adult↗
PubMed2000

Proton MR spectroscopy to assess axonal damage in multiple sclerosis and other white matter disorders.

Proton MR spectroscopy allows in vivo measurement of N-acetylaspartate in white matter, providing a biochemical index of axonal integrity. Several recent studies of patients with multiple sclerosis and other white matter disorders have shown both transient and sustained decreases in N-acetylaspartate in white matter lesions and in brain regions appearing normal on conventional MRI. These data have emphasised that a substantial amount of axonal damage or loss (presumably secondary to myelin pathology) is consistently present in most of these disorders. Recent post-mortem studies support these results. In contrast to changes seen with conventional MR imaging, decreases in N-acetylaspartate have shown a close correlation with changes in neurological status. This suggests that axonal damage may be more relevant than demyelination for determining chronic functional impairments in primary white matter diseases. Thus, serial measurement of brain N-acetylaspartate with proton MR spectroscopy can provide a reliable and clinically-relevant monitor of disease evolution. As pathological changes responsible for long-term morbidity are logically important targets for therapeutic agents, early treatment directed at axonal protection should be useful in these disorders.

Axons↗
PubMed1999

Association of trisomy 9p and band heterotopia.

Patients with the trisomy 9p syndrome and CNS abnormalities have been poorly assessed. We report a patient with trisomy 9p who showed band heterotopia on MRI. Abnormal neuronal migration is sufficiently frequent in patients with the trisomy 9p syndrome that brain MRI should be routinely considered in all patients with this syndrome.

Adult↗
PubMed1999

Detection of a rare Wilson disease mutation associated with arylsulfatase A pseudodeficiency.

We have studied a patient with Wilson disease (WD), belonging to a family segregating late-onset, dominant cerebellar ataxia. Analysis of the WD gene showed that the patient is a compound heterozygote, carrying the 14His1069Gln mutation from the father and the 8Gly710Ser mutation from the mother. The 8Gly710Ser is a mutation described previously only in a Swedish patient. Our patient is also homozygous for arylsulfatase A pseudodeficiency. This genetic defect, which has been reported in association with other neuropsychiatric syndromes, has not been described in WD.

Adult↗
PubMed1999

Acute inflammatory neuropathy in Charcot-Marie-Tooth disease.

The authors report an association between acute inflammatory neuropathy and previously undiagnosed Charcot-Marie-Tooth 1A disease in a 15-year-old girl. Sural nerve biopsy study showed hypertrophic neuropathy with endoneurial infiltrates of macrophages and lymphocytes. This association may be coincidental, but a particular susceptibility to damage of these peripheral nerves cannot be excluded. This report confirms the importance of pes cavus as a sign of long-standing sensorimotor neuropathy.

Action Potentials↗
PubMed1999

Detection of beta-A4 amyloid and its precursor protein in the muscle of a patient with juvenile neuronal ceroid lipofuscinosis (Spielmeyer-Vogt-Sjögren).

Muscle biopsy tissue from a patient affected by the juvenile form of neuronal ceroid lipofuscinosis (NCL) was studied immunohistochemically using antibodies to beta-amyloid peptide and amyloid precursor protein. Positive reaction in muscle was specifically localized to autophagic vacuoles and blood vessel walls. Increased acid phosphatase reaction suggested enhanced lysosomal activity. We hypothesize that beta-amyloid is deposited in NCL muscle by a lysosomal mechanism similar to that proposed in other disorders involving beta-amyloid.

Adult↗
PubMed1999

Studies on mitochondrial pathogenesis of Rett syndrome: ultrastructural data from skin and muscle biopsies and mutational analysis at mtDNA nucleotides 10463 and 2835.

In order to verify the pathogenic role of mitochondria in Rett syndrome, the results are reported of skin and muscle biopsies in two RS patients, showing morphological ultrastructural abnormalities in mitochondrial number and size. The investigation on two recently described mtDNA mutations (at nt 10463 and 2835) (Lewis et al., 1995; Tang et al., 1997) gave contrasting results with respect to previously reported data. In particular, the first mutation has been found in seven subjects, five of whom were from two different control groups, while the second mutation has been not detected in any of the 26 patients and controls. Although these results present some signs of a morphological impairment of mitochondria, they do not support the hypothesis that the two mutations may have a primary role in the pathogenesis of the syndrome and indicate the need for further investigations on the role of mtDNA in the pathogenesis of the syndrome.

Adolescent↗
PubMed1998

Mosaicism for full mutation and normal-sized allele of the FMR1 gene: a new case.

The main mutation in fragile X patients is the expansion of the CGG repeat in the first exon of the FMR1 gene, associated with hypermethylation of the proximal CpG island. An increasing number of atypical cases have been reported showing the coexistence of full mutation and premutated or normal-sized alleles. These genotypes are more difficult to detect, and if a PCR strategy alone is adopted, they can be incorrectly identified. We report on a fragile X man with severe phenotype and mosaicism for full mutation and a (CGG)7 normal allele, the shortest fragment reported as yet in mosaics. This case of mosaicism, as other similar cases previously reported, suggests that the normal-length allele can derive from a deletion during the same early stage of development in which the full mutation expansion also arose.

Adult↗
PubMed1998

Giant axonal neuropathy with subclinical involvement of the central nervous system: case report.

The case of a 17-year-old girl with slowly progressive sensory-motor neuropathy is described. Sural nerve biopsy showed abnormally enlarged exons filled with neurofilaments. Neurofilament accumulation was limited to the axons and was not found in other cells of the skin or peripheral nerve. The patient showed EEG and brain MRI abnormalities, but there was no clinical evidence of central nervous system involvement. Although these findings suggest an atypical attenuated form of giant axonal neuropathy, a new nosological entity cannot be excluded.

Adolescent↗
PubMed1998

Vitamin E serum levels in Rett syndrome.

In order to study the role of vitamin E in the pathogenesis of Rett syndrome (RS), we analysed vitamin E serum levels in twenty-eight patients affected by this disorder. We found lower vitamin E serum levels in nine cases (32.1%). These results indicated that the oxidative free radical metabolism may be impaired in a significant percentage of Rett syndrome patients suggesting the need for further studies of tissue vitamin E in different brain regions.

Adolescent↗
PubMed1998

Schnyder corneal crystalline dystrophy: description of a new family with evidence of abnormal lipid storage in skin fibroblasts.

Schnyder corneal crystalline dystrophy (SCCD) comprises corneal opacities often associated with precocious arcus senilis and genua valga. The metabolic defect seems to be related to abnormal lipid storage in the central part of the cornea, especially the anterior stroma, consisting mainly of nonesterified cholesterol. Plasma lipid levels are not always increased suggesting that the disease may be due to abnormal lipid metabolism limited to the cornea. We observed a family with typical SCCD, in 1 case associated with mental retardation and mild cerebellar hypoplasia. Results of serum lipid analysis of all patients were normal. Ultrastructural study of a skin biopsy specimen and fibroblast pellet showed membrane-bound spherical vacuoles containing lipid material. Cultured fibroblasts stained by filipin, a fluorescent probe that specifically binds unesterified cholesterol, showed abnormal cytoplasmic fluorescent material, suggesting abnormal cholesterol metabolism. The presence of neurological impairment, associated with SCCD in 1 of our cases, may be regarded as coincidental. Evidence of storage lipids in skin and cultured fibroblasts suggests that the disorder of intracellular cholesterol metabolism is not limited to the cornea and that skin biopsy may be a useful method to confirm the diagnosis.

Adult↗