Any mitochondrial complex IV deficiency in which the cause of the disease is a mutation in the PET117 gene. It is characterized by the onset of symptoms in infancy or early childhood. Affected individuals show global developmental delay and developmental regression with a loss of acquired motor and language skills. Additional features include motor dysfunction, such as hypokinesia and pyramidal signs. More variable features may include recurrent infections with immunodeficiency and possibly protein-losing enteropathy. The disease is mitochondrial complex IV deficiency, nuclear type 19 (MONDO_0033654). Also known as: MC4DN19.