Galactosialidosis, CTSA Sequencing
|Clinical info||Galactosialidosis is a lysosomal storage disease associated with a deficiency the lysosomal protective protein cathepsin A (PPCA), which aggregates with beta-galactosidase and sialidase enzymes to protect them from degradation. Therefore a deficiency of PCCA results in a secondary deficiency of these enzymes. There are 3 distinct subtypes, early infantile, late infantile, and juvenile/adult.
Clinical features common to late infantile and juvenile/adult subtypes include psychomotor delay and deterioration, hepatosplenomegaly, dysostosis multiplex, cherry-red macular spots and corneal clouding, heart defects, and renal involvement. Neurological symptoms are common to the juvenile/adult form, but rare in the late infantile form. The early infantile form is associated with hydrops fetalis, visceromegaly, skeletal dysplasia, and early death.
|Indications||Molecular testing is useful to confirm the diagnosis and to identify the disease causing mutation within a family to allow for carrier testing and prenatal diagnosis.|
Urine oligosaccharides is available in the Biochemical Diagnostic Lab and may be useful for screening for this disorder. Beta-galactosidase and sialidase/neuraminidase enzyme testing are also available and can be used to help establish the diagnosis.
|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||3 weeks|
|Prenatal testing||Prenatal diagnosis is available if the familial mutation is 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.|
Unknown mutation: 81479
|Cost||$1200 for full sequencing (unknown mutation)
$350 for known mutation
$700 for deletion/duplication analysisPrenatal diagnosis for a known mutation is $1000. Please contact the lab 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.