Only two disease-causing mutations have been reported in the Human Gene Mutation Database (HGMD, Professional version 2021.2) in the UFM1 gene so far, associated with global developmental delay, failure to thrive, progressive microcephaly, refractive epilepsy, and hypomyelination with atrophy of the basal ganglia and cerebellum phenotypes, and the same two mutations have been reported as pathogenic in the ClinVar database (Version accessed on 7 February 2021) associated with Hypomyelinating leukodystrophy type 14. This evidence concerns the gene UFM1 and Failure to thrive.