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E M Valente

Publications and source records attributed to E M Valente.

At least 19 recordsLinked to original sources
PubMed2006

Nephronophthisis type 1 deletion syndrome with neurological symptoms: prevalence and significance of the association.

Type 1 nephronophthisis (NPHP) with homozygous deletions of nephrocystin [NPHP1, DEL] has been considered a pure renal disorder, but co-occurrence of extrarenal symptoms, mainly retinitis pigmentosa, is observed in a subset of patients. Recently, [NPHP1, DEL] has been detected in three patients with Joubert syndrome-related disorders (JSRDs), who associated neurological signs with a peculiar neuroradiological malformation known as the 'molar tooth sign' (MTS). To define the frequency of JSRD spectrum in NPHP1 patients, we re-examined 56 cases with [NPHP1, DEL] and found an overall incidence of 8.9% (five out 56 patients). All had small hyperechoic kidneys and had developed advanced renal failure within 15 years. Two patients presented the complete features of JSRD with cerebello-renal-retinal association and MTS. Two others showed, instead, severe intentional tremor and thick superior cerebellar peduncles on brain magnetic resonance imaging (MRI), and one of them had associated retinopathy. The fifth patient presented with hypotonia, developmental delay, central deafness, and ataxia associated with Leber congenital amaurosis and liver fibrosis but with normal brain MRI. Marked intrafamilial variability of associated extrarenal symptoms was observed in familial cases. Deletion extension did not differ in patients with isolated renal phenotype and in those with associated neurological symptoms. In conclusion, neurological defects varying from subtle involvement of cerebellum with thickened peduncle to both JSRD and diffuse central hypotonia are frequent in [NPHP1, DEL] patients. Prevalence of such association may justify systematic neurological and neuroradiological evaluation.

Adolescent↗
PubMed2006

A family study on primary blepharospasm.

BACKGROUND: Previous family studies provided evidence that blepharospasm (BSP) can aggregate in families but did not give accurate and reliable information on the characteristics and degree of familial clustering. AIM: To evaluate the proportion of familial and non-familial BSP cases, the clinical expression of dystonia within families, the inheritance pattern, and the extent of penetrance. METHODS: The study was based on the examination of the first degree relatives of 56 probands with primary BSP. RESULTS: The 56 families produced a potential population of 436 first degree relatives of whom 296 were alive and 233 were examined. The proportion of index patients with at least one first degree relative affected by BSP, or adult onset dystonia other than BSP, was 27%. There was a remarkable degree of phenotypic variability of dystonia within families. Similar segregation ratios were calculated for probands' siblings and children. Under the assumption of autosomal dominant transmission of adult onset dystonia, penetrance was about 20%. CONCLUSIONS: The findings of this family study are relevant for accurately counselling the families of patients with BSP and may help identify the most appropriate study design to explore genetic susceptibility in BSP.

Adolescent↗
PubMed2005

The PINK1 phenotype can be indistinguishable from idiopathic Parkinson disease.

Mutations in the PINK1 gene cause autosomal recessive parkinsonism characterized by early onset and a variable phenotypic presentation. A patient homozygous for the Ala168Pro mutation has been fully characterized clinically. Apart from onset at age 39 years and the excellent and sustained response to levodopa, all clinical and laboratory features, including SPECT and assessment of autonomic function, were indistinguishable from typical idiopathic Parkinson disease.

Age of Onset↗
PubMed2005

The diverse phenotype and genotype of pantothenate kinase-associated neurodegeneration.

Pantothenate kinase-associated neurodegeneration (PKAN) is a rare autosomal-recessive disorder caused by mutations in the PANK2 gene. The authors report clinical and genetic findings of 16 patients with PKAN. The authors identified 12 mutations in the PANK2 gene, five of which were new. Only nine patients could be classified as classic or atypical PKAN, and intermediate phenotypes are described. Two patients presented with motor tics and obsessive-compulsive behavior suggestive of Tourette syndrome.

Adolescent↗
PubMed2005

The epsilon-sarcoglycan gene in myoclonic syndromes.

Mutations in the epsilon-sarcoglycan gene (SGCE) are associated with familial myoclonus dystonia, but the full spectrum of the phenotype may not be fully defined. We screened 58 individuals with a range of myoclonic/dystonic syndromes for SGCE mutations. We found mutations (three of them novel) in six (21%) of the 29 patients with essential myoclonus and myoclonic dystonia, but did not find mutations in the 29 patients with other phenotypes.

Age of Onset↗
PubMed2004

Clinical and genetic studies in hereditary spastic paraplegia with thin corpus callosum.

BACKGROUND: A complicated form of recessive hereditary spastic paraplegias (HSPs) with thin corpus callosum (TCC) was first described in Japan, and most of the Japanese families showed linkage to chromosome 15q13-15. A recessive HSP locus (SPG11) has also been mapped to chromosome 15q13-15 in Italian and North American families with and without TCC, and it overlaps the region identified in the Japanese families. OBJECTIVE: To study clinically and genetically 12 Italian families with HSP and TCC. METHODS: The authors investigated 18 affected and 30 healthy individuals from 12 unrelated Italian families with recessive HSP-TCC. Clinical, neurophysiologic, and neuroradiologic studies were undertaken. All patients were negative for SPG7 mutations. Genetic linkage analyses were carried out with polymorphic DNA markers on 15q13-15. RESULTS: Five families were consistent with linkage, thus defining a 19.8-cM region between markers D15S1007 and D15S978, encompassing the SPG11 interval. In one consanguineous family, linkage could be firmly excluded, confirming genetic heterogeneity. Two families appeared not linked to the region, but this could not be firmly proved because of the small family size. The remaining four families were uninformative for linkage purposes. CONCLUSION: HSP-TCC is common in Italy. The phenotype is fairly homogeneous and is associated with impaired cognition. There are at least two loci for HSP-TCC, one of which is on chromosome 15q13-15.

Adolescent↗
PubMed2004

DJ-1 mutations in Parkinson's disease.

Mutations in the DJ-1 gene have recently been shown to cause autosomal recessive Parkinson's disease. To estimate the prevalence of this mutation, an analysis was undertaken of 39 index cases of Parkinson's disease in whom a family history suggested autosomal recessive inheritance. No DJ-1 mutations were found in these patients, indicating that this gene is unlikely to be of numerical significance in clinical practice. The hypothesis was also tested that young onset Parkinson's disease patients in whom, despite extensive analysis, only a single heterozygous parkin mutation was found, might harbour a second mutation in the DJ-1 gene--that is, digenic inheritance. No patient was found with a single mutation in both DJ-1 and parkin genes, making this mode of inheritance unlikely. Finally it was confirmed that PARK6 and PARK7 (DJ-1), despite being phenotypically similar and mapping to the same small chromosomal region of 1p36, are caused by mutations in separate genes.

Age of Onset↗
PubMed2003

Infantile ascending hereditary spastic paralysis (IAHSP): clinical features in 11 families.

OBJECTIVE: To report clinical, neuroradiologic, neurophysiologic, and genetic findings on 16 patients from 11 unrelated families with a remarkable uniform phenotype characterized by infantile ascending hereditary spastic paralysis (IAHSP). METHODS: Sixteen patients from 11 families, originating from North Africa and Europe, who presented severe spastic paralysis and ascending progression were studied. RESULTS: Spastic paraplegia started in the first 2 years of life in most patients and extended to the upper limbs by the end of the first decade. The disease progressed to tetraplegia, anarthria, dysphagia, and slow eye movements in the second decade. The clinical course showed a long survival and preservation of intellectual skills. Clinical, neuroradiologic, and neurophysiologic findings were consistent with a relatively selective early involvement of the corticospinal and corticobulbar pathways. No signs of lower motor neuron involvement were observed, whereas motor evoked potentials demonstrated predominant involvement of the upper motor neurons. MRI was normal in young patients but showed brain cortical atrophy in the oldest, predominant in the motor areas, and T2-weighted bilateral hyperintense signals in the posterior arm of the internal capsule. The ALS2 gene, recently found mutated in consanguineous Arabic families with either an ALS2 phenotype or a juvenile-onset primary lateral sclerosis, was analyzed. Alsin mutations were found in only 4 of the 10 families, whereas haplotype analysis excluded the ALS2 locus in one family. CONCLUSIONS: The syndrome of IAHSP is genetically heterogeneous, and no clinical sign can help to distinguish patients with and without Alsin mutations.

Adolescent↗
PubMed2003

Role of the dopamine D5 receptor (DRD5) as a susceptibility gene for cervical dystonia.

Cervical dystonia (CD) is one of the most common forms of primary dystonia. The pathogenesis of the disease is still unknown, although evidence suggests a role for genetic factors. Recently, a polymorphism in the dopamine D5 receptor (DRD5) gene has been associated with the disease in a British population, suggesting that DRD5 is a susceptibility gene for CD. To confirm these data, we performed a case-control study of the microsatellite (CT/GT/GA)(n) at the DRD5 locus in 104 Italian CD patients and 104 healthy controls. The frequency of allele 4 was higher in the CD patients compared to the controls. This resulted in a twofold increased risk of developing the disease. These results provide further evidence of an association between DRD5 and cervical dystonia, supporting the involvement of the dopamine pathway in the pathogenesis of CD.

Adult↗
PubMed2003

Severe infantile hyperkalaemic periodic paralysis and paramyotonia congenita: broadening the clinical spectrum associated with the T704M mutation in SCN4A.

The authors describe an Italian kindred with nine individuals affected by hyperkalaemic periodic paralysis associated with paramyotonia congenita (hyperPP/PMC). Periodic paralysis was particularly severe, with several episodes a day lasting for hours. The onset of episodes was unusually early, beginning in the first year of life and persisting into adult life. The paralytic episodes were refractory to treatment. Patients described minimal paramyotonia, mainly of the eyelids and hands. All affected family members carried the threonine to methionine substitution at codon 704 (T704M) in exon 13 of the skeletal muscle voltage gated sodium channel gene (SCN4A). The association between T704M and the hyperPP/PMC phenotype has been only recently revealed. Nevertheless, such a severe phenotype has never been reported so far in families with either hyperPP or hyperPP/PMC. These data further broaden the clinical spectrum of T704M and support the evidence that this mutation is a common cause of hyperPP/PMC.

Adolescent↗
PubMed2002

PARK6 is a common cause of familial parkinsonism.

The Parkin gene is responsible for about 50% of autosomal recessive juvenile parkinsonism (ARJP) and less than 20% of sporadic early onset cases. We recently mapped a novel ARJP locus (PARK6) on chromosome 1p. Linkage to PARK6 was confirmed in 8 families from 4 different European countries. These families share some clinical features with the European Parkin-positive cases, with a wide range of ages at onset and slow progression. However, features typical of ARJP, such as dystonia and sleep benefit, were not observed, making the clinical presentation of late-onset cases indistinguishable from that of idiopathic PD. The determination of the smallest region of homozygosity in one consanguineous family allowed reducing the candidate interval to 9 cM. PARK6 appears to be an important locus for ARJP in Europe.

Chromosomes, Human, Pair 1↗
PubMed2001

Localization of a novel locus for autosomal recessive early-onset parkinsonism, PARK6, on human chromosome 1p35-p36.

The cause of Parkinson disease (PD) is still unknown, but genetic factors have recently been implicated in the etiology of the disease. So far, four loci responsible for autosomal dominant PD have been identified. Autosomal recessive juvenile parkinsonism (ARJP) is a clinically and genetically distinct entity; typical PD features are associated with early onset, sustained response to levodopa, and early occurrence of levodopa-induced dyskinesias, which are often severe. To date, only one ARJP gene, Parkin, has been identified, and multiple mutations have been detected both in families with autosomal recessive parkinsonism and in sporadic cases. The Parkin-associated phenotype is broad, and some cases are indistinguishable from idiopathic PD. In > or = 50% of families with ARJP that have been analyzed, no mutations could be detected in the Parkin gene. We identified a large Sicilian family with four definitely affected members (the Marsala kindred). The phenotype was characterized by early-onset (range 32-48 years) parkinsonism, with slow progression and sustained response to levodopa. Linkage of the disease to the Parkin gene was excluded. A genomewide homozygosity screen was performed in the family. Linkage analysis and haplotype construction allowed identification of a single region of homozygosity shared by all the affected members, spanning 12.5 cM on the short arm of chromosome 1. This region contains a novel locus for autosomal recessive early-onset parkinsonism, PARK6. A maximum LOD score 4.01 at recombination fraction .00 was obtained for marker D1S199.

Adult↗
PubMed2001

Phenotypic characterisation of autosomal recessive PARK6-linked parkinsonism in three unrelated Italian families.

The clinical features of nine patients (three women and six men) affected by PARK6-linked parkinsonism, belonging to three unrelated Italian families, are reported. The occurrence of affected men and women within one generation suggested an autosomal recessive mode of inheritance in all three families. Mean age at disease onset was 36 +/- 4.6 years; all cases except one presented with asymmetrical signs, consisting of tremor and akinesia of one upper limb or unilateral short step gait. Affected individuals had a mean age of 57 +/- 8.5 years, and average disease duration was 21 +/- 7.8 years. Parkinsonian features included benign course, early onset of drug-induced dyskinesias, and a good and persistent response to levodopa. There were no other associated features (i.e., pyramidal or cerebellar signs, dysautonomia, or diurnal fluctuations unrelated to drug treatment). Cognition was unaffected. The clinical picture was remarkably similar in all patients; no relevant family-related differences were found. PARK6 disease is a new form of early-onset parkinsonism without other atypical clinical features.

Adult↗
PubMed2001

Identification of a novel primary torsion dystonia locus (DYT13) on chromosome 1p36 in an Italian family with cranial-cervical or upper limb onset.

Primary torsion dystonia (PTD) is a clinically and genetically heterogeneous group of movement disorders, usually inherited in an autosomal dominant fashion. Three PTD loci (DYT1, DYT6 and DYT7) have been identified to date. However, in several PTD families linkage to the known loci has been excluded. We identified an Italian PTD family with 11 definitely affected members. Phenotype was characterised by juvenile or early-adult onset, prominent cranial-cervical and upper limb involvement, mild course and occasional generalisation. A genome-wide search performed in the family identified a novel PTD locus (DYT13) within a 22-cM interval on the short arm of chromosome 1, with a maximum lod score of 3.44 (theta = 0) between the disease and marker D1S2667.

Adolescent↗