Definitive diagnosis
Definitive diagnosis can be made in males by testing for deficient α-galactosidase A (α-GAL) enzyme activity in plasma, leukocytes, cultured skin fibroblasts, biopsied tissue, or dried blood, while diagnosis in females requires DNA analysis.1
Because females with Fabry disease can have α-GAL activity in the low to normal range in plasma, the patient should receive DNA analysis (either variant analysis or linkage analysis, depending on whether the family variant is known).1 Though an enzyme assay is not required for diagnosis, results can be helpful for understanding genotype-phenotype correlations.
If you suspect Fabry disease in a patient, testing is a straightforward process.1
Although females with a variant in the GLA gene may be asymptomatic or present with mild clinical manifestations, definitive identification of heterozygotes is important. Diagnosis allows practitioners to monitor for new or worsening symptoms and can help identify other family members with the disease.
Testing sites
Labs across the United States offer diagnostic tests for Fabry disease, and some provide the service free of charge.
Below are some options available to you and your patients.
*In free testing programs, patients may be responsible for nominal costs such as the cost of the blood draw and overnight shipping to the lab.
**GL3 is also known as GB-3. Lyso-GL3 is also known as Lyso-GB3.
This is not an all-inclusive list.
For additional testing centers that perform diagnostic testing, please visit www.ncbi.nlm.nih.gov/gtr/
This list of testing programs and/or laboratories is provided for informational use only. It should not be considered a recommendation or endorsement of any company, test, or service.
Physicians should contact the individual testing programs and/or laboratories for information on obtaining test requisitions, sample requirements, turnaround time, and the specific details of the services provided. For commercial lab testing, appropriate coding and obtaining reimbursement is the responsibility of the provider submitting a claim for the item or service.
Family screening
For every index patient diagnosed, an average of five additional affected family members may be identified.2 A Medical Family Tree is the first step in identifying other family members at risk of having Fabry disease. When you diagnose a Fabry patient, you make an earlier diagnosis possible for other family members.3
Test the patient, test the family
The Sanofi Patient Education Liaison
A Patient Education Liaison can help patients better understand the testing, genetic counseling, and disease management options available for them and their families.
The Medical Family Tree
Creating a pedigree in the form of a Medical Family Tree can help patients understand the inheritance pattern in their families and their risk of passing on Fabry disease. A Medical Genetic Counselor or Sanofi Patient Education Liaison can help patients complete their Medical Family Tree.
References
1. Desnick RJ, et al. In: The Online Metabolic and Molecular Bases of Inherited Diseases. New York, NY: McGraw Hill; 2014:1-64. 2. Laney DA, et al. J Genet Couns. 2008;17(1):79-83. 3. Nakao S, et al. Kidney Int. 2003;64(3):801-807.