RESUMO
Charcot-Marie-Tooth (CMT) disease type 1 is an inherited peripheral neuropathy characterized by demyelination and reduced nerve conduction velocities. We present a multi-generational family with peripheral neuropathy in whom clinical CMT panel testing failed to conclude a molecular diagnosis. We found a PMP2 pathogenic variant c.155Tâ¯>â¯C, p.(Ile52Thr) that segregates with disease suggesting that PMP2 variants should be considered in patients with neuropathy and that it may be prudent to include in clinical CMT gene panels.
Assuntos
Doença de Charcot-Marie-Tooth/genética , Proteína P2 de Mielina/genética , Patologia Molecular , Doenças do Sistema Nervoso Periférico/genética , Doença de Charcot-Marie-Tooth/diagnóstico , Doença de Charcot-Marie-Tooth/patologia , Doenças Desmielinizantes/genética , Doenças Desmielinizantes/patologia , Humanos , Mutação , Condução Nervosa/genética , Doenças do Sistema Nervoso Periférico/diagnóstico , Doenças do Sistema Nervoso Periférico/patologiaRESUMO
SOX5 encodes a transcription factor involved in the regulation of chondrogenesis and the development of the nervous system. Despite its important developmental roles, SOX5 disruption has yet to be associated with human disease. We report one individual with a reciprocal translocation breakpoint within SOX5, eight individuals with intragenic SOX5 deletions (four are apparently de novo and one inherited from an affected parent), and seven individuals with larger 12p12 deletions encompassing SOX5. Common features in these subjects include prominent speech delay, intellectual disability, behavior abnormalities, and dysmorphic features. The phenotypic impact of the deletions may depend on the location of the deletion and, consequently, which of the three major SOX5 protein isoforms are affected. One intragenic deletion, involving only untranslated exons, was present in a more mildly affected subject, was inherited from a healthy parent and grandparent, and is similar to a deletion found in a control cohort. Therefore, some intragenic SOX5 deletions may have minimal phenotypic effect. Based on the location of the deletions in the subjects compared to the controls, the de novo nature of most of these deletions, and the phenotypic similarities among cases, SOX5 appears to be a dosage-sensitive, developmentally important gene.
