Oculo-auriculo-vertebral spectrum with myopathy and velopharyngeal insufficiency. A case report with a non-branchiomeric muscle biopsy

In the present paper we report on a case of oculo-auriculo-vertebral spectrum presenting fluorescence in situ hybridization and comparative genomic hybridization tests negative, hypotonia of some branchiomeric muscles (with velo-pharyngeal insufficiency, dysphagia and nasal voice) and non-branchiomeric muscles (with strabismus and limb hypotrophy). On the basis of the left quadriceps muscle biopsy, showing anisometry and prevalence of type 1 fibers, and on literature data, we underline the relevance of TBX1 gene (regulator of neural crest cells and activator of myogenic factors in branchiomeric muscles development) and of PAX3 gene (present in neural crest, inducing migration of these cells and reported in non-branchiomeric muscles). We conclude that the case of OAVS presented a generalized myopathy and we hypothesize that a cluster of genes strictly neural crest cells related, including TBX1 and PAX3, may be responsible of the branchiomeric and non-branchiomeric myopathy; alternatively, a regulatory mechanism abnormally common to OAVS and velo-cardio-facial syndrome could be present.