OBJECTIVETo analyze the clinical features and genetic basis of a female neonate with muscle weakness, abnormal brain magnetic resonance imaging and elevated blood lactate.

METHODSThe patient was subjected to clinical and laboratory examination. Next generation sequencing was carried out for the patient and her relatives.

RESULTSThe proband was diagnosed as small for gestational age, with clinical features including muscle weakness, abnormal brain magnetic resonance imaging, increased blood lactate, and acidosis. By genetic testing, a de novo PDHA1 mutation c.1133G to A (p.R378H) was identified, which was known to be pathogenic. The patient was diagnosed with pyruvate dehydrogenase complex deficiency disease (PDCDD), for which vitamin B1, coenzyme Q10, and L-carnitine were prescribed, and a ketogenic diet was recommended. Follow-up at 4-month-7-day found that her blood lactic acid was reduced to normal but her muscle tone was still low.

CONCLUSIONThe proband was diagnosed as PDCDD caused by a PDHA1 missense mutation. NGS has provided a powerful tool for the diagnosis of such diseases.