SPEF2 and ataxia telangiectasia: After variant filtering and a functional analysis, ∼28% of patients had an identified genetic cause of AT, including gene mutations previously reported by our group (i.e. DNAH10 (Tu et al., 2021), DRC3 (Zhou et al., 2023a), DNHD1 (Tan et al., 2022), SPEF2 (Tu et al., 2020a), CFAP54 (Tian et al., 2023), TTC12 (Meng et al., 2023), and CFAP65 (Wang et al., 2021)), and other unreported mutations.