Severe cases of CLA manifest in the neonatal period; milder cases caused by mtDNA mutations may not manifest until as late as early adulthood. Symptoms may be constant or brought on by an event causing stress, such as an
asthma attack,
seizure, or
infection. Symptoms in the neonatal period include
hypotonia,
lethargy,
vomiting, and
tachypnea. As the disease progresses, it causes
developmental delay,
cognitive disabilities, abnormal development of the face and head, and
organ failure. == Pathogenesis ==