ITPR1 and cerebellar ataxia: ITPR1 variants have already been described as possibly corresponding to four different phenotypes: multi-exon deletions in ITPR1 gene to spinocerebellar ataxia type 15 (SCA15, OMIM #606658), single nucleotide variants to spinocerebellar ataxia type 29 (SCA29, OMIM #117360) or ataxic cerebral palsy (Ataxic CP), and the truncated and splice-site variants in Gillespie Syndrome (GLSP, OMIM #206700) also presented ataxia and balance disturbances [37–42].