Neonatal succinate-CoA ligase deficiency presented as mild methylmalonic aciduria: a case report / 中华围产医学杂志

ABSTRACT

To report a case of neonatal succinate-CoA ligase deficiency with mild methylmalonic aciduria caused by SUCLG1 compound heterozygous mutation. Our proband developed the disease at the 2nd day of life, manifested by vomiting and milk rejection. Blood gas analysis indicated metabolic acidosis and hyperlactacidemia. Laboratory tests showed mild hyperammonemia, mild elevation of serum aminotransferase and normal homocysteine. Imageology examination showed brain dysplasia and multiple cardiac malformations. Mild methylmalonic aciduria was suggested by blood acylcarnitines and urine organic acids analysis. Two novel mutations, c.40A>G (p.M14V) and a heterozygous deletion of exon 6 to 9, were identified by whole-exome sequencing in SUCLG1, which came from the mother and father, respectively. Metabolic acidosis turned better by volume expansion and acidosis correction, but lactic acidosis was persistent. Edema and respiratory failure occurred, after which the parent gave up treatment and the patient died after discharged from hospital. The mutations of SUCLG1 gene lead to succinate-CoA ligase deficiency and mitochondrial DNA depletion syndrome. There is no specific treatment for this disease. For infants with feeding difficulties, lactic acidosis and multiple organ damage, metabolic abnormality screening should be performed. Genetic analysis is the diagnostic method.