Two novel mutations in DNAJC12 identified by whole‐exome sequencing in a patient with mild hyperphenylalaninemia

Abstract

Abstract Background Recently hyperphenylalaninemia (HPA) caused by variants in DNAJC12 was reported and this suggested a new strategy for diagnosis. But DNAJC12‐associated HPA is a rare in Chinese population so far. Methods The clinical information and blood samples from the patient and his family members were collected and analyzed. Whole‐exome sequencing (WES) was used to identify the causative gene. Results We reported a newborn patient with HPA, having excluded the causes in common genes associated with HPA. By using whole‐exome sequencing, novel compound heterozygosity mutations in DNAJC12 were found, namely c.306C>G (p.His102Gln) and c.182delA (p.Lys61Argfs*6). Administering a diet with low phenylalanine combined with tetrahydrobiopterin and neurotransmitter precursors were shown to be effective in preventing neurodevelopmental delay for these patients. Conclusion Our finding confirms the diagnosis of DNAJC12‐associated HPA and suggests that genetic detection of DNAJC12 should be considered when newborn screening results are positive for HPA.

Keywords

• DNAJC12
• hyperphenylalaninemia
• whole‐exome sequencing