title: Comprehensive cDNA study and quantitative analysis of mutant HADHA and HADHB transcripts in a French cohort of 52 patients with mitochondrial trifunctional protein deficiency.
abstract: BACKGROUND
  Deficiency of mitochondrial trifunctional protein (MTP) is caused by mutations in the HADHA and HADHB genes, which have been mostly delineated at the genomic DNA level and have not been always elucidated.
  
  
  OBJECTIVE
  To identify mutations in a French cohort of 52 MTP deficient patients and the susceptibility of mutations generating premature termination codons (PTCs) to the nonsense mRNA mediated decay (NMD).
  
  
  METHODS
  Mutation screening in fibroblasts was performed at the cDNA level and real-time RT-PCR was used to compare the levels of the different PTC-bearing mRNAs before and after a treatment of fibroblasts by emetine, a translation inhibitor.
  
  
  RESULTS
  A mutation detection rate of 100% was achieved. A total of 22 novel mutations were identified, including a large-sized genomic deletion in HADHB gene. A high proportion of all identified mutations were non-sense, frameshift and splicing mutations, generating (PTCs), distributed essentially on HADHA coding regions. We could demonstrate that the majority of mutations resulting in PTCs conform to the established rules governing the susceptibility to NMD.
  
  
  CONCLUSIONS
  Our results emphasize the value of cDNA analysis in the characterization of HADHA and HADHB mutations and further strengthen the model of haploinsufficiency as a major pathomechanism in MTP defects.
authors.affiliation: Biochimie, Hopital de Bicêtre, Hôpitaux Universitaires Paris-Sud, APHP, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Boutron
authors.forename: C
authors.initials: C
authors.lastname: Acquaviva
authors.forename: C
authors.initials: C
authors.lastname: Vianey-Saban
authors.forename: P
authors.initials: P
authors.lastname: de Lonlay
authors.forename: H Ogier
authors.initials: HO
authors.lastname: de Baulny
authors.forename: N
authors.initials: N
authors.lastname: Guffon
authors.forename: D
authors.initials: D
authors.lastname: Dobbelaere
authors.forename: F
authors.initials: F
authors.lastname: Feillet
authors.forename: F
authors.initials: F
authors.lastname: Labarthe
authors.forename: D
authors.initials: D
authors.lastname: Lamireau
authors.forename: A
authors.initials: A
authors.lastname: Cano
authors.forename: T Billette
authors.initials: TB
authors.lastname: de Villemeur
authors.forename: A
authors.initials: A
authors.lastname: Munnich
authors.forename: J M
authors.initials: JM
authors.lastname: Saudubray
authors.forename: D
authors.initials: D
authors.lastname: Rabier
authors.forename: O
authors.initials: O
authors.lastname: Rigal
authors.forename: M
authors.initials: M
authors.lastname: Brivet
mesh_terms: D001483:Base Sequence; D015331:Cohort Studies; D018076:DNA, Complementary / Q000235:genetics*; D005260:Female; D005602:France; D057895:Haploinsufficiency; D006801:Humans; D052439:Lipid Metabolism Disorders / Q000235:genetics*; D008297:Male; D028361:Mitochondrial Diseases / Q000235:genetics*; D024101:Mitochondrial Proteins / Q000235:genetics*; D063991:Mitochondrial Trifunctional Protein; D063992:Mitochondrial Trifunctional Protein, alpha Subunit; D063993:Mitochondrial Trifunctional Protein, beta Subunit; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics*; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D018076:DNA, Complementary; D024101:Mitochondrial Proteins; D009097:Multienzyme Complexes; C576205:HADHA protein, human; D063992:Mitochondrial Trifunctional Protein, alpha Subunit; C576206:HADHB protein, human; D063991:Mitochondrial Trifunctional Protein; D063993:Mitochondrial Trifunctional Protein, beta Subunit