Gaucher Disease Molecular DNA Assay

Definition

Gaucher disease (GD) molecular DNA testing identifies mutations in the acid Ž ²-glucosidase (GBA) gene in carriers and affected individuals. Glucosylceramidase enzyme activity is very low in affected individuals, but enzyme assay is not recommended for detection of GBA gene mutation carriers. Carrier testing should be accomplished through DNA testing of the GBA gene.
Normal values: negative or no mutations are found.

Carrier testing for Ashkenazi Jewish individuals
Carrier testing for at-risk family members of affected individuals
For carrier testing use:
- Targeted mutation analysis:
  - A panel of four common mutations comprising (legacy mutation name in parenthesis):
    - p.N409S (Asn370Ser), p.L483P (Leu444Pro), c.84dupG (84GG), c.115+1G>T, (IVS2+1G>A)
    - More extended panels include additional less common mutations such as:
    - p. V433L (Val394Leu), p.D448H (Asp409His), p.R502C (Arg463Cys), p.R535H (Arg496His), g.5879del55 (1263del55)
Confirmatory diagnosis in symptomatic individuals use:
- GBA gene sequence analysis: Analysis of the entire coding region and exon " “intron boundaries is useful for identifying rare mutant alleles associated with GD.
Prenatal diagnosis " ”when both parental mutations are known use:
- Mutation-specific testing for known familial mutations

The results of a genetic test may be affected by DNA rearrangements, blood transfusion, bone marrow transplantation, or rare sequence variations.