Autosomal recessive deafness-70 (DFNB70) is a neurologic disorder with a variable disease course. All individuals present with isolated congenital sensorineural hearing loss in infancy that appears to be stable for the first decades of life. Affected members of 1 family with longer follow-up developed a neurodegenerative disease in their forties, including ataxia with loss of ambulation, optic atrophy, dystonia or spasticity, and cognitive decline with psychiatric features. The later onset of additional symptoms in this family suggests that others with DFNB70 may be at risk of developing multisystem disease in mid-to-late adulthood. These reports indicate that there is a phenotypic spectrum of PNPT1-related disease manifestations (Von Ameln et al., 2012; Eaton et al., 2018). [from
OMIM]