Novel Nonsense Calmodulin-Binding Transcription Activator 1 Mutation Presenting as a Tremor-Predominant Phenotype.

A 25-year-old right-handed male presented with head and bilateral arm and leg tremor. His symptoms began at age 10 years with action tremor of both hands and progressed in severity with time. He had difficulty with social interactions but did not have intellectual disabilities. His past medical history was significant for obsessive compulsive disorder and anxiety, asthma, gastroesophageal reflux disease, and scoliosis; and his family history was significant for tremor in his father and paternal grandfather. Genetic testing was performed and identified a deleterious sequence variation in exon 19 of the calmodulin-binding transcription activator 1 (CAMTA1) gene. The presence of this sequence variation was confirmed in the patient and in his affected father. The case is novel because of tremor predominance and because the mutation is a sequence variation rather than a deletion or duplication.