A pseudodeficiency allele (D152N) of the human beta-glucuronidase gene (original) (raw)

We present evidence that a 480G-->A transition in the coding region of the beta-glucuronidase gene, which results in an aspartic-acid-to-asparagine substitution at amino acid position 152 (D152N), produces a pseudodeficiency allele (GUSBp) that leads to greatly reduced levels of beta-glucuronidase activity without apparent deleterious consequences. The 480G-->A mutation was found initially in the pseudodeficient mother of a child with mucopolysaccharidosis VII (MPSVII), but it was not on her disease-causing allele, which carried the L176F mutation. The 480G-->A change was also present in an unrelated individual with another MPSVII allele who had unusually low beta-glucuronidase activity, but whose clinical symptoms were probably unrelated to beta-glucuronidase deficiency. This individual also had an R357X mutation, probably on his second allele. We screened 100 unrelated normal individuals for the 480G-->A mutation with a PCR method and detected one carrier. Reduced beta...