TTN and Parkinson disease: The same variant affecting leucyl-tRNA synthetase 2, mitochondrial (LARS2), encoding for a mitochondrial aminoacyl-tRNA synthetase, which is downregulated in the dopaminergic neurons of the substantia nigra in PD, was detected in 2/3 patients, while two different variants were documented in 2/3 patients in the titin (TTN) gene.