title: [A preliminary study of plasma microRNA levels in children with methylmalonic acidemia].
abstract: OBJECTIVE
  To screen out differentially expressed microRNAs (miRNAs) in the plasma of children with methylmalonic acidemia (MMA), to determine the expression of miR-9-1 in plasma and to preliminarily evaluate the significance of miR-9-1 as a biomarker in MMA.
  
  
  METHODS
  Plasma was obtained from 17 MMA children, 10 hyperhomocysteinemia (HHcy) children without MMA (HHcy group), and 10 normal controls. Of 17 MMA children, 12 had HHcy (MMA+HHcy group), and 5 had no HHcy (MMA group). The differentially expressed miRNAs were screened out by miRNA microarray. Differentially expressed miR-9-1 was selected, and plasma miR-9-1 levels were determined by RT-PCR. Urine was collected from MMA patients who received vitamin B12 treatment, and plasma miR-9-1 levels were determined by RT-PCR after treatment.
  
  
  RESULTS
  The miRNA microarray analysis showed that 26 miRNAs were differentially expressed, among which 16 miRNAs (including miR-9-1) were down-regulated over 2 times, while 10 miRNAs were up-regulated over 2 times. The MMA+HHcy , MMA and HHcy groups had significantly down-regulated miR-9-1 compared with the normal control group (P<0.01). The patients who showed a good response to vitamin B12 treatment had significantly increased plasma miR-9-1 levels, without significant difference compared with the normal control group.
  
  
  CONCLUSIONS
  Plasma miR-9-1 is significantly down-regulated in MMA patients, but it is significantly up-regulated after vitamin B12 treatment, suggesting that miR-9-1 may act as a biomarker in monitoring the progression of MMA.
authors.affiliation: Department of Neurology, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China. jiayanjie1971@yahoo.com.cn.
authors.forename: Yan-Fei
authors.initials: YF
authors.lastname: Li
authors.forename: Tao
authors.initials: T
authors.lastname: Peng
authors.forename: Ran-Ran
authors.initials: RR
authors.lastname: Duan
authors.forename: Xiao-Han
authors.initials: XH
authors.lastname: Wang
authors.forename: Hui-Li
authors.initials: HL
authors.lastname: Gao
authors.forename: Jing-Tao
authors.initials: JT
authors.lastname: Wang
authors.forename: Jun-Fang
authors.initials: JF
authors.lastname: Teng
authors.forename: Yan-Jie
authors.initials: YJ
authors.lastname: Jia
mesh_terms: D000293:Adolescent; D000592:Amino Acid Metabolism, Inborn Errors / Q000235:genetics*; D002648:Child; D005260:Female; D006801:Humans; D020138:Hyperhomocysteinemia / Q000235:genetics; D008297:Male; D035683:MicroRNAs / Q000097:blood*
chemical_list: C541874:MIRN92 microRNA, human; D035683:MicroRNAs