OXA1L and Global developmental delay: We used whole exome sequencing to identify recessively inherited variants in OXA1L (NM_005015.3; c.500_507dup, p.(Ser170Glnfs*18) and c.620G>T, p.(Cys207Phe) in a patient with a mitochondrial disorder, presenting at birth with hypotonia, severe encephalopathy and developmental delay.