The GeneDx clinical ataxia gene panel identified maternally inherited (Figure 1) synonymous variant (NM_000051.3a: c.2250G > A) in the ATM. The c.2250G > A variant is rare in the population databases (0.00004387 in gnomAD v2.1.1; 0.00002630 in gnomAD v3.1.1; and 0.000026446 in TopMed database freeze 8) and only present in the heterozygous state. Here, ATM is linked to cerebellar ataxia.