Neonatal isovaleric acidemia in China: A case report and review of literature.

BACKGROUND: Isovaleric acidemia (IVA) is a rare autosomal recessive inherited organic acidemia caused by a genetic deficiency of isovaleryl-CoA dehydrogenase (IVD). Its morbidity is low, but mortality is high. There is no effective cure for this disease. Early identification of IVA using clinical features can significantly slow disease progression and reduce mortality. Here we report a Chinese neonate with two mutations of IVD and share valuable information on this disease.

CASE SUMMARY: A 12-day-old male neonate with "poor response for 1 d and repeated convulsions accompanied by high muscle tension for 6 h" was hospitalized. The patient was the first child of nonconsanguineous ethnic Chinese parents. He was delivered by cesarean section due to breech position at 39 + 1 wk of gestation with a birth weight of 3.27 kg. Initially, he suffered from dyspnea and rhinobyon, and at 10 d after birth the patient suddenly developed poor feeding, low response, lethargy and seizures. Organic acid analysis of blood and urine by tandem mass spectrometry and gas chromatography mass spectrometry showed extremely high concentrations of isovaleryl glycine. The patient had an acute episode of IVA causing severe metabolic stress and eventually died.

CONCLUSION: A new case of an IVA patient carrying c.1193G>A (p.Arg398Gln) and c.1208A>G (p.Try403Cys) mutations is reported in China.