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Test Includes | This test covers all coding nucleotides of gene MYH7, plus at least two and typically 20 flanking intronic nucleotides upstream and downstream of each coding exon, covering the conserved donor and acceptor splice sites, as well as typically 20 flanking nucleotides in the 5′ and 3′ UTR. |
Special Instructions | In cases in which a known mutation can be documented, the physician may prefer to order test 252579.
Test orders must include an attestation that the provider has the patient’s informed consent for genetic testing. See sample physician office consent form: Consent for Genetic Testing. In the case of family tests (ie, known mutations), please submit the result report of the first patient tested in the family (the index case), if not performed at a LabCorp facility. Other family members are subsequently tested for the specific mutation found in the first patient tested. |
Specimen | Whole blood; DNA is accepted (Call 866-647-0735 for DNA collection information.) |
Volume | 2 mL |
Container | Lavender-top (EDTA) tube |
Collection | Samples may be stored for brief periods at 4°C. Ship overnight at room temperature. |
Storage Instructions | Maintain specimen at room temperature. |
Causes for Rejection | Container broken or leaking; container not labeled or label not legible |
Reference Interval | Normal equals reference sequence or variants that are known or predicted to be benign; abnormal equals all other variants. |
Use | Confirm a clinical diagnosis of HCM; identify presymptomatic family members, guiding prophylactic measures |
Limitations | This method does not reliably detect mosaic variants; large deletions; large duplications, inversions, or other rearrangements; or deep intronic variants. It may be affected by allele-dropout, it may not allow determination of the exact numbers of T/A or microsatellite repeats, and it does not allow any conclusion as to whether two heterozygous variants are present on the same or on different chromosome copies.
This test was developed, and its performance characteristics determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA). |
Methodology | DNA sequencing |
Additional Information | Hypertrophic cardiomyopathy (HCM) is a common, dominantly inherited genetic disease characterized by a thickening of the heart muscle that can lead to severe cardiac problems such as progressive heart failure, embolic stroke, and sudden death. Mutations in MYH7 account for 25% to 40% of HCM, and mutation carriers typically have 40% to 50% risk of developing symptoms. Genetic testing can confirm a clinical diagnosis of HCM and allow for accurate identification of presymptomatic mutation carriers within affected families. |
References | Alcalai R, Seidman JG, Seidman CE. Genetic basis of hypertrophic cardiomyopathy: From bench to the clinics. J Cardiovasc Elecrophysiol. 2008 Jan; 19(1):104-110. PubMed 17916152
Bos JM, Towbin JA, Ackerman MJ. Diagnostic, prognostic, and therapeutic implications of genetic testing for hypertrophic cardiomyopathy. J Am Coll Cardiol. 2009 Jul 14; 54(3):201-211. PubMed 19589432 |