RESUMEN
Mutations in the surfactant protein (SP)-B gene are responsible for SP-B deficiency in congenital alveolar proteinosis (CAP) (Nogee et al. J Clin Invest 1994: 93: 1860-1883; Lin et al. Mol Genet Metab 1998: 64: 25-35; Klein et al. Pediatrics 1998: 132: 244-248; Ballard et al. Pediatrics 1995: 96: 1046-1052). The multigenerational consanguineous pedigree under study does not carry any of the known mutations, although this pedigree had 14 infant deaths following respiratory distress at birth. Immunostaining of the lungs from three such infants revealed decreased or absent SP-B. By sequencing of SP-B exons, exon-intron junctions, and the 5' and 3' flanking regions, nine polymorphisms were found in this pedigree, but none of them could explain the observed SP-B deficiency. Further analysis of SP-B mRNA by reverse transcription-polymerase chain reaction from paraffin-embedded lung tissue of CAP patients showed that SP-B mRNA is not intact. Although the sequence of mRNA from exon 1-exon 7 and from exon 8-exon 10 could be amplified, the region between exons 7 and 8 could not. From fluorescence in situ hybridization of the short arm of chromosome 2p, only 2 signals were identified, eliminating the possibility of translocation as the cause of the SP-B mRNA aberrance. Although the nature of the genetic basis of SP-B deficiency in this family is currently unknown, the existence of aberrant SP-B mRNA may, at least in part, be responsible for the SP-B deficiency in this pedigree.
Asunto(s)
Pulmón/metabolismo , Proteolípidos/genética , Proteinosis Alveolar Pulmonar/congénito , Surfactantes Pulmonares/genética , ARN Mensajero/análisis , Cromosomas Humanos Par 2 , Cartilla de ADN/química , Exones , Femenino , Frecuencia de los Genes , Humanos , Hibridación Fluorescente in Situ , Recién Nacido , Intrones , Pulmón/patología , Masculino , Mutación , Linaje , Polimorfismo Genético , Polimorfismo de Longitud del Fragmento de Restricción , Proteinosis Alveolar Pulmonar/genética , Proteinosis Alveolar Pulmonar/metabolismo , Proteinosis Alveolar Pulmonar/patología , Surfactantes Pulmonares/deficiencia , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Chordoma is a rare tumour of the skeleton that develops from notochordal elements. It occurs in the midline of the body particularly at the upper and lower ends of the vertebral columns. This paper reports a case of chordoma of unusual localization in the transverse process of a lumbar vertebra in a 30-year-old man with review of the literature. The early confinement of the tumour to a vertebral transverse process has never been reported. The scarcity with which chordoma is diagnosed in Jordan and the clinical presentation of the case reported are discussed.