A Variant in TBCD Associated with Motoneuronopathy and Corpus Callosum Hypoplasia: A Case Report

Mutations in the tubulin-specific chaperon D (TBCD) gene, involved in the assembly and disassembly of the & alpha;/& beta;-tubulin heterodimers, have been reported in early-onset progressive neurodevelopment regression, with epilepsy and mental retardation. We describe a rare homozygous variant in TBCD, namely c.881G>A/p.Arg294Gln, in a young woman with a phenotype dominated by distal motorneuronopathy and mild mental retardation, with neuroimaging evidence of corpus callosum hypoplasia. The peculiar phenotype is discussed in light of the molecular interpretation, enriching the literature data on tubulinopathies generated from TBCD mutations.

Automated summary

Mutations in the TBCD gene lead to neurodevelopment regression, epilepsy, and mental retardation. We report a rare homozygous variant in TBCD, causing distal motorneuronopathy and mild mental retardation, with evidence of corpus callosum hypoplasia on neuroimaging. The molecular interpretation of this unique phenotype expands the literature on tubulinopathies associated with TBCD mutations.