LALD can be diagnosed using a blood test that measures the amount of lysosomal acid lipase (LAL) enzyme activity in the blood. People with LALD have little to no LAL enzyme activity.
Low LAL enzyme activity confirms the LALD diagnosis, and no further testing is required to diagnose LALD.
Genetic testing of the LIPA, the gene that encodes instructions for making the LAL enzyme, is also informative, though testing the enzyme level alone is enough to confirm the LALD diagnosis. Genetic testing can usually identify the causative LIPA gene variants, and genetic testing is required for testing family members who may be carriers, and for testing future pregnancies. It is also essential to identify the LIPA gene variants for preimplantation genetic diagnosis (PGD). PGD enables families to utilize assisted reproductive technology called in vitro fertilization, and test the embryo for LALD before a pregnancy is established, almost eliminating the possibility of having a child with LALD. It’s also often possible to learn about the expected presentation associated with different genetic variants.
Due to technical limitations in genetic testing methodologies, it is not always possible to identify two variants in the LIPA gene in rare cases, even for patients who are affected with LALD and have very low LAL enzyme activity. However, this does not rule out LALD, because the enzyme test is diagnostic, even if two variants are not identified.
If you are not currently diagnosed with LAL-D but have signs or symptoms and want to be tested, please contact your doctor or see our list of Selected LALD Treatment Centers to find a doctor specializing in LALD.
Genetic counseling is recommended for all patients and family members undergoing genetic testing.