The human TUBB3 gene is located on chromosome 16q24.3, and consists of 4 exons that transcribe a protein of 450aa. A shorter isoform of 378aa derived from alternative splicing of exon 1 is devoid of part of the N-terminus and may be responsible for mitochondrial expression.
Researchers have identified a series of heterozygous missense mutations in TUBB3, encoding the neuron-specific beta-tubulin isotype III, that result in a spectrum of human nervous system disorders we now call the TUBB3 syndromes. Each mutation causes the ocular motility disorder CFEOM3, whereas some also result in intellectual and behavioral impairments, facial paralysis, and/or later-onset axonal sensorimotor polyneuropathy. Neuroimaging reveals a spectrum of abnormalities including hypoplasia of oculomotor nerves, and dysgenesis of the corpus callosum, anterior commissure, and corticospinal tracts.
Different TUBB3 variations affect each person differently. We have found that they way the person affected with a TUBB3 mutation presents varies greatly from person to person. Some show minimal symptoms and some show a lot more and the mutation affects them much more dramatically. Each person is different, but there are still a lot of similarities.
For more information on ongoing research, you can visit:
http://www.childrenshospital.org/research-and-innovation/research/labs/engle-laboratory/neurodevelopmental-research/tubb3