Various kinds of genetic and epigenetic changes can cause growth failure before and after birth. Through screening of a cohort of babies born small for gestational age, we have encountered a 6-year-old boy with prenatal growth restriction and some specific physical features. Detailed molecular analyses have revealed epigenetic alteration (epimutation) of the ZNF597 gene on chromosome 16. This is the first report describing the possible relationship between the ZNF597 gene and growth failure in children. (Epi)genetic test for ZNF597 may be worth considering for small babies of unknown etiology. (By Dr. Kazuki Yamazawa, https://jmg.bmj.com/content/early/2020/06/23/jmedgenet-2020-107019 )