RESUMO
We describe a family with parental consanguinity and five of 10 siblings affected by late-onset autoimmune myasthenia gravis. We propose a genetic mechanism as a predisposing factor in this family. Our analysis excludes the major histocompatibility complex, the beta subunit of the acetylcholine receptor, and the T-cell receptor alpha and beta subunits as candidate genes for the disorder in this family.
Assuntos
Miastenia Gravis/genética , Idoso , Autoanticorpos/genética , Southern Blotting , Feminino , Antígenos HLA/genética , Humanos , Masculino , Miastenia Gravis/imunologia , Linhagem , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores Colinérgicos/imunologiaRESUMO
Charcot-Marie-Tooth disease (CMT), also known as hereditary motor and sensory neuropathy, is a heterogeneous group of slowly progressive, degenerative disorders of peripheral nerve. X-linked CMT (CMTX) (McKusick 302800), a subdivision of type I, or demyelinating, CMT is an X-linked dominant condition with variable penetrance. Previous linkage analysis using RFLPs demonstrated linkage to markers on the proximal long and short arms of the X chromosome, with the more likely localization on the proximal long arm of the X chromosome. Available variable simple-sequence repeats (VSSRs) broaden the possibilities for linkage analysis. This paper presents new linkage data and recombination analysis derived from work with four VSSR markers--AR, PGKP1, DXS453, and DXYS1X--in addition to analysis using RFLP markers described elsewhere. These studies localize the CMTX gene to the proximal Xq segment between PGKP1 (Xq11.2-12) and DXS72 (Xq21.1), with a combined maximum multipoint lod score of 15.3 at DXS453 (theta = 0).