An increasing number of reports have investigated families with Sengers syndrome and via whole-exome sequencing identified different types of mutations in the AGK gene, and patients with different AGK mutations show clinical heterogeneity (Mayr et al., 2012; Siriwardena et al., 2013; Haghighi et al., 2014; Beck et al., 2018; Aggarwal et al., 2021). Here, AGK is linked to Sengers syndrome.