More severe neurodevelopmental conditions, characterized by developmental delay, impaired growth, dysmorphic facies, and axonal neuropathy (known as DIGFAN, MIM: #619090), have also been reported (Guillen Sacoto et al., 2020; Duan et al., 2021a; Lassuthova et al., 2016). This evidence concerns the gene MORC2 and axonal neuropathy.