title: Identification of novel mutations in the α-galactosidase A gene in patients with Fabry disease: pitfalls of mutation analyses in patients with low α-galactosidase A activity.
abstract: BACKGROUND
  Fabry disease is an X-linked lysosomal storage disorder caused by mutations of the α-galactosidase A (GLA) gene, and the disease is a relatively prevalent cause of left ventricular hypertrophy followed by conduction abnormalities and arrhythmias. Mutation analysis of the GLA gene is a valuable tool for accurate diagnosis of affected families. In this study, we carried out molecular studies of 10 unrelated families diagnosed with Fabry disease.
  
  
  METHODS
  Genetic analysis of the GLA gene using conventional genomic sequencing was performed in 9 hemizygous males and 6 heterozygous females. In patients with no mutations in coding DNA sequence, multiplex ligation-dependent probe amplification (MLPA) and/or cDNA sequencing were performed.
  
  
  RESULTS
  We identified a novel exon 2 deletion (IVS1_IVS2) in a heterozygous female by MLPA, which was undetectable by conventional sequencing methods. In addition, the g.9331G>A mutation that has previously been found only in patients with cardiac Fabry disease was found in 3 unrelated, newly-diagnosed, cardiac Fabry patients by sequencing GLA genomic DNA and cDNA. Two other novel mutations, g.8319A>G and 832delA were also found in addition to 4 previously reported mutations (R112C, C142Y, M296I, and G373D) in 6 other families.
  
  
  CONCLUSIONS
  We could identify GLA gene mutations in all hemizygotes and heterozygotes from 10 families with Fabry disease. Mutations in 4 out of 10 families could not be identified by classical genomic analysis, which focuses on exons and the flanking region. Instead, these data suggest that MLPA analysis and cDNA sequence should be considered in genetic testing surveys of patients with Fabry disease.
authors.affiliation: Division of Cardiac Repair and Regeneration, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Yoshimitsu
authors.forename: Koji
authors.initials: K
authors.lastname: Higuchi
authors.forename: Masaaki
authors.initials: M
authors.lastname: Miyata
authors.forename: Sean
authors.initials: S
authors.lastname: Devine
authors.forename: Andre
authors.initials: A
authors.lastname: Mattman
authors.forename: Sandra
authors.initials: S
authors.lastname: Sirrs
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Medin
authors.forename: Chuwa
authors.initials: C
authors.lastname: Tei
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Takenaka
mesh_terms: D000328:Adult; D000368:Aged; D024741:Cardiomyopathy, Hypertrophic, Familial / Q000150:complications; D018076:DNA, Complementary / Q000032:analysis; D000795:Fabry Disease / Q000235:genetics*; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D021141:Nucleic Acid Amplification Techniques; D012313:RNA / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D000519:alpha-Galactosidase / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D012313:RNA; D000519:alpha-Galactosidase