The mutation spectrum of SLC25A13 gene in citrin deficiency: identification of novel mutations in Vietnamese pediatric cohort with neonatal intrahepatic cholestasis

Abstract

Background: Citrin deficiency (CD), a disorder caused by mutations in the SLC25A13 gene, may result in neonatal intrahepatic cholestasis. This study was purposely to explore the mutation spectrum of SLC25A13 gene in Vietnamese CD patients.

Methods: The 292 unrelated CD patients were first screened for four high-frequency mutations by PCR/PCR-RFLP. Then, Sanger sequencing was performed directly for heterozygous or undetected patients. Novel mutations identified would need to be confirmed by their parents.

Results: 12 pathogenic SLC25A13 mutations were identified in all probands, including three deletions c.851_854del (p.R284Rfs*3), c.70-63_133del (p.Y24_72Ifs*10), and c.[1956C>A;1962del] (p.[N652K;F654Lfs*45]), two splice-site mutations (IVS6+5G>A and IVS11+1G>A), one nonsense mutations c.1399C>T (p.R467*), one duplication mutation c.1638_1660dup (p.A554fs*570), one insertion IVSl6ins3kb (p.A584fs*585), and four missense mutation c.2T>C (p.M1T), c.1231G>A (p.V411M), c.1763G>A (p.R588Q), and c.135G>C (p.L45F). Among them, c.851_854del (mut I) was the most identified mutant allele (91.78%) with a total of 247 homozygous and 42 heterozygous genotypes of carriers. Interestingly, two novel mutations were identified: c.70-63_133del (p.Y24_72Ifs*10) and c.[1956C>A;1962del] (p.[N652K;F654Lfs*45]).

Conclusion: The SLC25A13 mutation spectrum related to intrahepatic cholestasis infants in Vietnam revealed a quite similar pattern to Asian countries' reports. This finding supports the use of targeted SLC25A13 mutation for CD screening in Vietnam and contributed to the SLC25A13 mutation spectra worldwide. It also helps emphasize the role of DNA analysis in treatment, genetic counseling, and prenatal diagnosis.