[CLPB gene mutations analysis in a case of type 3-methylglutaconic aciduria].

Objective: To validate the diagnosis of an infant with elevated urine 3-methylglutaconic acid (3-MGA) through sequencing of the CLPB gene.

Methods: Genomic DNA of the infant was sequenced by next generation sequencing (NGS), and candidate pathogenic variants were verified by Sanger sequencing and bioinformatics analysis.

Results: NGS has revealed that the infant has carried a c.1085G>A (p.Arg362Gln) and a c.1700A>C (p.Tyr567Ser) of the CLPB gene, which were respectively inherited from her parents. Among these, c.1085G>A (p.Arg362Gln) is a novel variant which was unreported previously, and based on the ACMG guidelines, it was predicted to be a possible pathogenic variant.

Conclusion: Compound heterozygous variants c.1085G>A (p.Arg362Gln) and c.1700A>C (p.Tyr567Ser) of the CLPB gene probably underlay the disease in this infant. Genetic testing has confirmed the diagnosis.