A Novel De Novo TUBB3 Variant Causing Developmental Delay, Epilepsy and Mild Ophthalmological Symptoms in a Chinese Child

AbstractHeterozygous missense mutations inTUBB3 have been implicated in various neurological disorders encompassing either isolated congenital fibrosis of the extraocular muscles type 3 (CFEOM3) or complex cortical dysplasia with other brain malformations 1 (CDCBM1). The description of seizures in patients withTUBB3 mutations is rare. Here, we reported a patient who had febrile seizures before and focal seizure this time, which was diagnosed as epilepsy in combination with an abnormal EEG. MRI showed hypoplastic corpus callosum. Mutation analysis showed a novel de novo heterozygous variant of theTUBB3 gene (NM_006086), c.763G  >  A (p.V255I). The patient had global developmental delay, photophobia and elliptic pupils, but lacking extraocular muscle involvement and malformations of cortical development, which might be a less severe phenotype ofTUBB3 mutations. This is the first report of elliptic pupils in a patient withTUBB3 mutations and expands the spectrum ofTUBB3 phenotypes. It indicates that the phenotypic range ofTUBB3 mutations might exist on more of a continuum than as a discrete entity, with severity ranging from mild to severe. Further studies are needed to elucidate the complete spectrum ofTUBB3-related phenotypes.
Source: Journal of Molecular Neuroscience - Category: Neuroscience Source Type: research