Parkinsonism and essential tremor in a family with pseudo-dominant inheritance of PARK2: an FP-CIT SPECT study.

We report a family with 5 affected individuals manifesting either essential tremor (ET), Parkinsonism, or both, consistent with pseudo-dominant inheritance of PARK2. Two homozygotes presented postural and kinetic tremor several years before the onset of Parkinsonism. Postural and kinetic tremor mimicking ET was the only feature in 1 homozygous and 2 heterozygous carriers of the mutation. Striatal dopamine transporter density was reduced in accordance with phenotype and number of mutated alleles. In 3 homozygotes and 1 heterozygote, a 2-year follow-up single photon emission computed tomography suggested no progression of nigrostriatal deficit.