A rare autosomal recessive microcephalic primordial dwarfism with characteristics of congenital microcephaly and craniofacial features associated with a spectrum of limb abnormalities ranging from mild to severe. Short stature is frequently observed and often is severe. The disorder is due to bi-allelic mutations in the downstream neighbour of SON, DONSON (21q22.11), a replisome component that stabilises forks during genome replication. [from SNOMEDCT_US]