RESUMO
OBJECTIVE: To characterize a new gene locus for familial spastic paraparesis (FSP). BACKGROUND: FSP is a genetically heterogeneous group of upper motor neuron syndromes. It can be inherited as an autosomal dominant, autosomal recessive, or X-linked disorder. Four loci for autosomal dominant FSP have been genetically mapped, and two genes have been shown responsible for the X-linked type. In addition, two loci for autosomal recessive type have been reported and mapped to chromosomes 8q and 16q. The gene for the 16q locus has been characterized as a mitochondrial protein. METHODS: Eight recessive FSP families from America and Europe were used for genetic linkage analysis. The known recessive loci (8q and 16q) and the X-linked loci (PLP and L1CAM genes) were screened through PCR amplification, followed by linkage analysis, single-strand conformational polymorphism, or both. RESULTS: All the families except one revealed lack of linkage to the known loci for recessive and X-linked types of FSP. One of the eight families showed data consistent with linkage to the previously characterized 8q locus. Analysis of all the families for possible linkage to other candidate loci revealed significant positive lod scores for markers in chromosome 15q. The maximum multipoint combined lod score for the non-8q families was Z = 3.14 for markers D15S1007, D15S971, D15S118, and D15S1012, at a distance of 6.41 cM from the marker D15S1007, in between D15S971 and D15S118. CONCLUSIONS: Our data suggest a new locus for recessive FSP linked to chromosome 15q, and that this may be the most common one.
Assuntos
Cromossomos Humanos Par 15 , Genes Recessivos , Paraplegia Espástica Hereditária/genética , Adolescente , Adulto , Idade de Início , Mapeamento Cromossômico , Feminino , Marcadores Genéticos , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Linhagem , Polimorfismo Conformacional de Fita Simples , Porto Rico , Estados UnidosRESUMO
Results of audiometric studies carry out in fifty patients previously diagnosed as bilateral corthipathy caused by chronic acoustic trauma. The studies were performed with the same audiometer in a silent chamber, and out of it, in a audiology service from a social security institution along 1988. The analysis of results show that both procedures have the same accuracy for the assessment of the audiologic level, and are confidential for the diagnosis and evaluation of secuelae.