Gaucher Disease (GBA) Sequencing
|Clinical info||Gaucher disease, a lysosomal storage disorder, can present with a wide spectrum of severity ranging from a perinatal lethal phenotype to asymptomatic. There are three primary types with two additional subtypes, all categorized by differences in the clinical presentation of the patient. Hepatosplenomegaly, pulmonary disease, and cytopenia are also common for most types of Gaucher disease.
Patients with Gaucher disease type 1 have varying degrees and types of bone disease as the primary feature, but do not have any central nervous system involvement. Gaucher disease types 2 and 3 present with primary neurologic disease. Type 2 and 3 are distinguished based on age of onset and disease progression. Patients with type 2 typically have an earlier onset before age 2, rapid disease progression, and early death. Type 3 is characterized by a slower disease course with patients living into adulthood. Neurologic findings for types 2 & 3 include bulbar signs, pyramidal signs, oculomotor apraxia, seizures, as well as dementia and ataxia in later disease stages.
The perinatal lethal form may present as nonimmune hydrops fetalis or with pyramidal neurologic signs and ichthyosiform skin changes. The cardiovascular form is characterized by primarily by calcification of mitral and aortic values with other minor findings.
|Indications||Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutations within a family to allow for carrier testing and prenatal diagnosis.|
|Associated Tests||Enzyme testing for β-glucosidase activity is available in the Biochemical Diagnostic Laboratory and can be used to help establish the diagnosis.|
|Detection||Sequencing of the GBA gene will detect mutations in about 99% of individuals with enzymatically confirmed Gaucher disease.|
|Specimen Requirements||5 to 10 ml of peripheral blood collected in an EDTA (lavender top) Vacutainer tube is preferred. The minimal blood needed for reliable DNA isolation is 3 ml.|
|Transport||The specimen should be kept at room temperature and delivered via overnight shipping. FedEx is preferred. If shipment is delayed by one or two days, the specimen should be refrigerated and shipped at room temperature. Do not freeze the specimen. Samples collected on Friday can be safely designated for Monday delivery.|
|Turnaround time||21 days|
|Prenatal testing||Prenatal diagnosis is available if the familial mutations are known. Additional fees for cell culture and maternal cell contamination may apply. Maternal cell contamination studies are required for all prenatal molecular tests. Contact the laboratory prior to sending a prenatal specimen.|
|CPT Codes||Unknown mutation: 81479
Known mutation: 81403
Deletion/Duplication Analysis: 81405
|Cost||$1000 for sequencing
$350 for known mutation
$700 for deletion/duplication analysis
Prenatal diagnosis for known mutation is $1000. Please contact the laboratory for more information.
Molecular Diagnostic Lab
The Molecular Diagnostic Lab offers DNA analysis for many genetic disorders via gene sequencing, targeted mutation analysis, MLPA deletion/duplication testing, trinucleotide repeat analysis and next generation sequencing panels.