CASQ2 Mutation Analysis
Calsequestrin 2 is a calcium-binding protein located in the lumen of sarcoplasmic reticulum in cardiomyocytes. This protein is encoded by the CASQ2 gene which is composed of 11 exons and is located at 1p13.3-p11. Calsequestrin 2 forms a complex with RyR2 and functions in the regulation of calcium in the sarcoplasmic reticulum of the cardiomyocyte.
Multiple mutations have been identified in both CASQ2 and RYR2 in patients with catecholamine-induced polymorphic ventricular tachycardia (CPVT). CASQ2 mutations have been documented to cause autosomal recessive CPVT. However, some evidence suggests that CASQ2 mutations may also result in CPVT by means of autosomal dominant transmission with low penetrance or multifactorial inheritance.
The John Welsh Cardiovascular Diagnostic Laboratory offers molecular genetic testing for CASQ2 mutations. Individuals will be tested by automatic fluorescent DNA sequencing of all 11 exons of the CASQ2 gene. We strongly recommend initial testing of an affected individual, if available, in order to provide the greatest test sensitivity and clearest interpretation of results for subsequent family members. Genetic counseling is recommended for all individuals in order to identify additional at-risk family members and to discuss reproductive issues.
Reasons for Referral
Molecular confirmation of the diagnosis of catecholamine-induced polymorphic ventricular tachycardia resulting from CASQ2 mutations
Genomic DNA will be analyzed for CASQ2 mutations by automatic fluorescent DNA sequencing of all 11 exons of the CASQ2 gene, as well as the exon/intron junctions and a portion of the 5′ and 3′ untranslated regions. Patient DNA will be sequenced in both the forward and reverse orientations. If a mutation is identified, additional family members will be analyzed only for the familial mutation(s) by automatic fluorescent DNA sequencing.
|Service||Direct and Institutional Billing||CPT Codes|
|Index Case (Male or Female)||$750 per sample||81406, G0452|
|Additional Family Members||$300 per sample; known familial mutation only||81403, G0452|
DNA Sequencing Analysis: Approximately 99 percent detection of mutations in exons 1-11 of CASQ2.
Blood (preferred): EDTA (purple-top) tubes: Adult: 5 cc, Child: 5 cc, Infant: 2-3 cc
Tissue: Frozen (preferred), RNAlater, Formalin-fixed, Paraffin-embedded
Other Body Fluids: Call to inquire
Buccal Swabs: One swab from each cheek
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