PMPCA and neurodegenerative disease: In early childhood SCAR2 is categorized by beginning of decreased motor development and ataxic gait.9 Autosomal recessive cerebellar ataxias are complex, heterogeneous, disabling inherited neurodegenerative diseases connecting both the peripheral and central nervous systems.10 Studies over the past few years have illuminated the genetic underpinnings of SCAR2, linking it to mutations in the PMPCA gene.