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BioMed Research International
Volume 2016, Article ID 4124263, 7 pages
http://dx.doi.org/10.1155/2016/4124263
Research Article

Identification of a Large SLC25A13 Deletion via Sophisticated Molecular Analyses Using Peripheral Blood Lymphocytes in an Infant with Neonatal Intrahepatic Cholestasis Caused by Citrin Deficiency (NICCD): A Clinical and Molecular Study

1Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
2Core Laboratory, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China
3Biomedical Translational Research Institute, Jinan University, Guangzhou 510630, China

Received 3 January 2016; Accepted 23 February 2016

Academic Editor: Patrizia Cardelli

Copyright © 2016 Qi-Qi Zheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. Neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) is a Mendelian disorder arising from biallelic SLC25A13 mutations, and SLC25A13 genetic analysis was indispensable for its definite diagnosis. However, conventional SLC25A13 analysis could not detect all mutations, especially obscure large insertions/deletions. This paper aimed to explore the obscure SLC25A13 mutation in an NICCD infant. Methods. Genomic DNA was extracted to screen for 4 high-frequency SLC25A13 mutations, and then all 18 exons and their flanking sequences were analyzed by Sanger sequencing. Subsequently, cDNA cloning, SNP analyses, and semiquantitative PCR were performed to identify the obscure mutation. Results. A maternally inherited mutation IVS16ins3kb was screened out, and then cDNA cloning unveiled paternally inherited alternative splicing variants (ASVs) featuring exon 5 skipping. Ultimately, a large deletion c.329-1687_c.468+3865del5692bp, which has never been described in any other references, was identified via intensive study on the genomic DNA around exon 5 of SLC25A13 gene. Conclusions. An NICCD patient was definitely diagnosed as a compound heterozygote of IVS16ins3kb and c.329-1687_c.468+3865del5692bp. The large deletion enriched the SLC25A13 mutation spectrum, and its identification supported the concept that cDNA cloning analysis, along with other molecular tools such as semiquantitative PCR, could provide valuable clues, facilitating the identification of obscure SLC25A13 deletions.