Fabry disease: identification of novel alpha-galactosidase A mutations and molecular carrier detection by use of fluorescent chemical cleavage of mismatches

Biochem Biophys Res Commun. 1999 Apr 21;257(3):708-13. doi: 10.1006/bbrc.1999.0310.


Fabry disease (FD) (angiokeratoma corporis diffusum) is an X-linked inborn error of glycosphingolipid metabolism caused by defects in the lysosomal alpha-galactosidase A gene (GLA). The enzymatic defect leads to the systemic accumulation of neutral glycosphingolipids with terminal alpha-galactosyl moieties. Clinically, affected hemizygous males have angiokeratoma, severe acroparesthesia, renal failure, and vasculopathy of the heart and brain. While demonstration of alpha-galactosidase deficiency in leukocytes is diagnostic in affected males, enzymatic detection of female carriers is often inconclusive, due to random X-chromosomal inactivation, underlining the need of molecular investigations for accurate genetic counseling. By use of chemical cleavage of mismatches adapted to fluorescence-based detection systems, we have characterized the mutations underlying alpha-Gal A deficiency in 16 individuals from six unrelated families with FD. The mutational spectrum included five missense mutations (C202W, C223G, N224D, R301Q, and Q327K) and one splice-site mutation [IVS3 G(-1) --> C]. Studies at the mRNA level showed that the latter led to altered pre-mRNA splicing with consequent alteration of the mRNA translational reading frame and generation of a premature termination codon of translation. By use of this strategy, carrier status was accurately assessed in all seven at-risk females tested, whereas enzymatic dosages failed to diagnose or exclude heterozygosity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Base Pair Mismatch / genetics*
  • Base Sequence
  • Codon, Terminator / genetics
  • DNA / genetics
  • DNA / metabolism*
  • DNA Mutational Analysis
  • Dosage Compensation, Genetic
  • Exons / genetics
  • Fabry Disease / blood
  • Fabry Disease / diagnosis
  • Fabry Disease / genetics*
  • Female
  • Fluorescent Dyes
  • Genetic Carrier Screening / methods*
  • Humans
  • Male
  • Molecular Sequence Data
  • Mutation*
  • Mutation, Missense / genetics
  • Pedigree
  • RNA Splicing / genetics
  • Sensitivity and Specificity
  • alpha-Galactosidase / blood
  • alpha-Galactosidase / chemistry
  • alpha-Galactosidase / genetics*


  • Codon, Terminator
  • Fluorescent Dyes
  • DNA
  • alpha-Galactosidase