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S Teijeira

Publications and source records attributed to S Teijeira.

9 recordsLinked to original sources
PubMed2003

Neuromuscular disorders in the Gypsy ethnic group. A short review.

The Roma (Gypsies) are a transnational minority with an estimated population of 10 to 14 million, 8 of which reside in Europe, scattered between the Balkans and Western countries. Similar to other genetically isolated founder populations, the Roma harbour a number of unique or rare autosomal recessive disorders, caused by "private" founder mutations. These genetically homogeneous populations are a unique resource for research into disease phenotypes, genotype/phenotype correlations and possible factors modifying clinical severity. Regarding neuromuscular diseases, the following have been identified: limb girdle muscular dystrophy type 2C also called gamma-sarcoglycanopathy, congenital myasthenic syndrome type 1a, spinal muscular atrophy, and three novel hereditary sensorimotor neuropathies, namely -Lom, -Russe and the congenital cataracts facial dysmorphism neuropathy syndrome. In 1996, a novel demyelinating neuropathy in the Roma was described and the gene was mapped in 8q24. Almost simultaneously, a founder mutation in the gamma-sarcoglycan gene in a group of 24 Romani patients from France, Spain and Italy was discovered by a different group of researchers. The cooperation between these two groups and people from several European countries was fruitful, and in 2001 the 91st Workshop of the European Neuromuscular Center was organized to discuss the above-mentioned diseases in the Roma. Full papers on each of the topics were subsequently published in the 20th Anniversary volume of Acta Myologica, in December 2001. Here, we present a short review of neuromuscular disorders in Gypsies and we discuss the perspectives and future for further studying and research.

Europe↗
PubMed2001

Molecular heterogeneity of myophosphorylase deficiency (McArdle's disease): a genotype-phenotype correlation study.

We report on 54 Spanish patients with McArdle's disease from 40 unrelated families. Molecular analysis revealed that the most common R49X mutation was present in 70% of patients and 55% of alleles. The G204S mutation was less frequent and found in 14.8% of patients and 9% of mutant alleles. The W797R mutation was observed in 16.5% of patients, accounting for 13.7% of mutant alleles. Moreover, 78% of mutant alleles among Spanish patients can be identified by using polymerase chain reaction-restriction fragment length polymorphism analysis for the R49X, G204S, and W797R mutations, which makes noninvasive diagnosis possible through molecular genetic analysis of blood DNA. Six novel mutations were found. Three were missense mutations, E348K, R601W, and A703V; two nonsense mutations, E124X and Q754X; and one single base pair deletion, 533 delA. No clear genotype-phenotype correlation emerges from our study. Most of the mutations of uncharged and solvent inaccessible residues and the truncations must disrupt the basic structure of the protein. The mutations of charged residues would be expected to interfere with internal hydrogen bonding networks, introducing severe incompatible partnering that is caused by poor packing or electrostatic repulsions.

Adolescent↗
PubMed2000

A novel missense mutation (W797R) in the myophosphorylase gene in Spanish patients with McArdle disease.

OBJECTIVE: To investigate the degree of genetic heterogeneity of myophosphorylase deficiency (McArdle disease) in Spain through molecular studies of 10 new patients. DESIGN: The coding sequence of the entire myophosphorylase gene was sequenced in DNA extracted from muscle and blood. Restriction fragment length polymorphism analysis of polymerase chain reaction fragments was used to confirm and simplify detection of a novel mutation. SETTING: A collaborative study between 2 university laboratories in Spain and the United States. RESULTS: Five of the 10 patients harbored a novel missense mutation in exon 20, converting a tryptophan to an arginine (W797R). Three patients were homozygous for the "common" R49X mutation, and the remaining 2 patients were compound heterozygotes for R49X and a previously described missense mutation, G204S. CONCLUSIONS: The W797R missense mutation is the third novel mutation to be identified among Spanish patients. Its relative frequency suggests that it should be added to the R49X mutation in the molecular screening of McArdle disease in Spain.

Adult↗
PubMed2000

Evaluation of heart involvement in gamma-sarcoglycanopathy (LGMD2C). A study of ten patients.

Thorough non-invasive cardiovascular studies were conducted in a series of ten gamma-sarcoglycanopathy Gypsy patients with the founder C283Y mutation in 13q12. Results were compared with those obtained in an age-matched group of normal boys and girls. The studies included electrocardiographic and echocardiographic evaluations using pulsed wave Doppler tissue imaging to assess regional diastolic function and myocardial velocities at various levels. This study confirms the significant electrocardiographic abnormalities described in previous studies. Furthermore, measurement of myocardial velocity at different levels demonstrated an abnormal relaxation pattern in the tricuspid annulus in four of the oldest patients, which strongly suggests intrinsic myocardial involvement of the right ventricle. To our knowledge, these specific studies have not been previously performed in a clinically and genetically homogeneous group of gamma-sarcoglycanopathy patients and suggest primary myocardial involvement probably due to gamma-sarcoglycan deficiency in cardiac muscle fibres. Our results could be of interest in the follow-up of these patients and the prevention and treatment of late cardiological complications.

Adolescent↗
PubMed1999

Adult glycogenosis II with paracrystalline mitochondrial inclusions and Hirano bodies in skeletal muscle.

Hirano bodies constitute eosinophilic intracytoplasmic inclusions, typically seen in the central nervous system, where they are related to senility and certain dementias such as Alzheimer's disease or the Parkinson-dementia complex. They have been found in different tissues of experimental animals and, on rare occasions, in extraocular muscles of elderly individuals. However, to our knowledge they have not been described in skeletal muscle in locations other than extraocular muscles or associated with muscle pathology. Glycogenosis II or Pompe's disease, is a metabolic disorder caused by acid maltase deficiency and is characterized by glycogen accumulation in lysosomes in various tissues, including skeletal muscle. There are three clinical forms depending on age at onset, the most frequent being the childhood form. We present the histopathological and ultrastructural findings of a muscle biopsy performed in a case of the adult form of glycogenosis II which showed, in addition to characteristic lysosomal glycogen storage, paracrystalline mitochondrial inclusions and, as an exceptional finding, intracytoplasmic Hirano bodies in some muscle fibres.

Female↗
PubMed1998

Subsarcolemmal expression of utrophin in neuromuscular disorders: an immunohistochemical study of 80 cases.

The immunohistochemical expression of utrophin in 80 muscle biopsies from patients with dystrophinopathies and other neuromuscular disorders is reported. All biopsy specimens were routinely studied by a battery of 12 histoenzymatic techniques, and immunohistochemistry was performed for spectrin, three domains of dystrophin and two domains of utrophin. Abnormal utrophin expression was observed in all dystrophinopathic muscles compared with normal controls or biopsy samples from several other muscular diseases. Inflammatory myopathies presented abnormal overexpression of utrophin and an abnormal dystrophin immunolabeling pattern. This overexpression of utrophin appears to be directly related to the decrease in dystrophin. We conclude that the study of utrophin is important for the histological interpretation and differential diagnosis of dystrophin-related muscular disorders.

Adolescent↗
PubMedDate not supplied

Isolated progressive muscle weakness with tubular aggregates.

We report 2 isolated cases of slowly progressive muscle weakness in which tubular aggregates in muscle biopsy were found as the major pathological feature. Tubular aggregates were present in both types of fibers. Electron microscopy revealed the accumulation of double-walled tubular structures in dense subsarcolemmal locations or in smaller amounts within the myofibrils, close to cytoplasmic organelles. Myopathy with tubular aggregates is believed to form a distinct clinico-pathological entity with 3 well-distinguished clinical groups. The cases reported herein would fall into the group of sporadic isolated progressive muscle weakness of which only 3 other cases have been previously described.

Adult↗