Lichtenstein-Knorr syndrome
An autosomal recessive spinocerebellar ataxia caused by disease-causing variants in the SLC9A1 gene, characterized by early-onset cerebellar ataxia, cognitive or developmental delay, seizure, and cerebellar atrophy. Patients may also present with varying degrees of nystagmus, oculomotor apraxia, amelogenesis imperfecta and sensorineural hearing loss.