Objective: To explore whether SLC25A13 gene mutation exists and what is its mutation spectrum in mainland Chinese infants with intrahepatic cholestasis and abnormal blood amino acids.
Methods: Blood amino acids were analyzed by mass chromatographic analysis in infants referred to Fudan University Children's Hospital from June 2003 to June 2007 for investigations of intrahepatic cholestasis of unknown origin. SLC25A13 gene mutations were studied in 14 children whose serum levels of citrulline and/or methionine were at least two times above the upper normal range. In patients in whom only one mutation was detected, all other exons and their neighboring sequences were then analyzed.
Results: Eight patients with SLC25A13 gene mutations, including 2 with compound heterozygous mutation 851del4/1638ins23, one with homozygous mutation 851del4/851del4, one with compound heterozygous mutation 851del4/R184X, one with homozygous mutation IVS6+1G more than A/IVS6+1G more than A, and 3 with heterozygous mutation 851del4 were found.
Conclusions: SLC25A13 gene mutations exist in Chinese infants with intrahepatic cholestasis and abnormal blood amino acids. Their mutation spectrum is different from that in Japan. 851del4 is the most common mutation in our study. IVS6+1G more than A is a mutation that has not been reported before.