title: 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.
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.
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China.
authors.forename: Qi-Qi
authors.initials: QQ
authors.lastname: Zheng
authors.affiliation: Core Laboratory, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China.
authors.forename: Zhan-Hui
authors.initials: ZH
authors.lastname: Zhang
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China.
authors.forename: Han-Shi
authors.initials: HS
authors.lastname: Zeng
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China.
authors.forename: Wei-Xia
authors.initials: WX
authors.lastname: Lin
authors.affiliation: Biomedical Translational Research Institute, Jinan University, Guangzhou 510630, China.
authors.forename: Heng-Wen
authors.initials: HW
authors.lastname: Yang
authors.affiliation: Biomedical Translational Research Institute, Jinan University, Guangzhou 510630, China.
authors.forename: Zhi-Nan
authors.initials: ZN
authors.lastname: Yin
authors.affiliation: Department of Pediatrics, The First Affiliated Hospital, Jinan University, Guangzhou 510630, China.
authors.forename: Yuan-Zong
authors.initials: YZ
authors.lastname: Song
mesh_terms: D002780:Cholestasis, Intrahepatic / Q000175:diagnosis / Q000209:etiology / Q000235:genetics*; D002874:Chromosome Mapping / Q000379:methods*; D020159:Citrullinemia / Q000150:complications / Q000175:diagnosis / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000379:methods*; D017353:Gene Deletion; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007231:Infant, Newborn; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D033681:Mitochondrial Membrane Transport Proteins / Q000097:blood / Q000235:genetics*; D025202:Molecular Diagnostic Techniques; D020641:Polymorphism, Single Nucleotide / Q000235:genetics
chemical_list: D005819:Genetic Markers; D033681:Mitochondrial Membrane Transport Proteins; C119629:SLC25A13 protein, human