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HelpTest Code LAB3141 HCM Gene Panel
Additional Codes
HCM Pnl
Clinical System Name
HCM Gene Panel
Synonyms
Hypertrophic Cardiomyopathy (HCM)
Transthyretin Amyloidosis
Wolff-Parkinson-White Syndrome
Danon Disease
Sample Requirements
Preferred Specimen: Whole Blood
Container(s): Lavender/EDTA
Preferred Vol: 5.0 mL
Minimum Vol: 2.0 mL (1.0 mL is acceptable for infants)
Alternative Specimen: DNA
Container(s): Sterile Plastic Tube
Preferred Vol: 5 µg at a concentration of ≥50 ng/µL AND a volume of ≥100 µL
Alternative Specimen: Buccal Swab
Processing Instructions
Reject due to:
Spin: N
Aliquot: N
Temp: 2 - 8 C
Storage Location: Do not spin. Affix large Epic label(s) to tube(s) and place in CPA refrigerator, Send Outs rack.
Off-site Collection:
Stability
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood | Room Temp | 3 d |
| Refrigerated | 7 d | |
| Frozen | N | |
| Extracted DNA | Room Temp | 3-4 d |
| Refrigerated | 1 y | |
| Frozen | Indefinitely |
Availability
| STAT | Performed | TAT |
|---|---|---|
| N | 4 wks |
Performing Laboratory
GeneDx
207 Perry Parkway
Gaithersburg, MD 20877
Phone Number: (301) 519-2100
Department
Department: Send Outs/Genetic
Phone Number: (206) 987-2563
Methodology
Method: Next-generation sequencing with CNV calling (NGS-CNV)
The technical sensitivity of sequencing is estimated to be >99% at detecting single nucleotide events. It will not reliably detect deletions greater than 20 base pairs, insertions or rearrangements greater than 10 base pairs, or low-level mosaicism. The copy number assessment methods used with this test cannot reliably detect copy number variants of less than 500 base pairs or mosaicism and cannot identify balanced chromosome aberrations. Assessment of exon-level copy number events is dependent on the inherent sequence properties of the targeted regions, including shared homology and exon size. For mitochondrial genome testing, sequencing analysis is performed on the following genes: MTND1, MTND5, MTND6, MTTD, MTTG, MTTH, MTTI, MTTK, MTTL1, MTTL2, MTTM, MTTQ, MTTS1, and MTTS2. Next-generation sequencing may not detect mtDNA point variants present at 10% heteroplasmy or lower.
Reportable variants include pathogenic variants, likely pathogenic variants and variants of uncertain significance. Likely benign and benign variants, if present, are not routinely reported.
Reference Range
Interpretive report provided.
Send Out Instructions
| Reference Test Name: | Hypertrophic Cardiomyopathy (HCM) Panel |
| Reference Lab Test Code: | J553 |
| Instructions: |
Ship Monday through Friday via FedEx Priority Overnight. Saturday deliveries are accepted. |
Description
This panel includes analysis of genes associated with Hypertrophic cardiomyopathy (HCM).
This panel includes genes: ACTC1, ACTN2, ALPK3, CAV3, CSRP3, FHL1, FLNC, GAA, GLA, JPH2, LAMP2, MTND1, MTND5, MTND6, MTTD, MTTG, MTTH, MTTI, MTTK, MTTL1, MTTL2, MTTM, MTTQ, MTTS1, MTTS2, MYBPC3, MYH6, MYH7, MYL2, MYL3, MYOZ2, PLN, PRKAG2, RAF1, RIT1, TCAP, TNNC1, TNNI3, TNNT2, TPM1, TTR, VCL
Clinical Utility
Hypertrophic cardiomyopathy (HCM) is a disease of the cardiac muscle characterized by left ventricular hypertrophy (LVH), myocyte disarray, and fibrosis. Symptoms may include shortness of breath, chest pain, palpitations, fatigue, fainting (syncope), and heart failure. Nonetheless, some affected individuals have no symptoms or remain clinically stable. Age of onset spans childhood to adulthood, and the clinical phenotype is variable, even within the same family. HCM is also the most common cause of sudden cardiac death in the young (<30 years of age) and in athletes.
The clinical diagnosis is often established by the observation of LVH on cardiac imaging such as echocardiogram in the absence of a predisposing cardiac or cardiovascular condition (e.g. hypertension or aortic stenosis). HCM is caused by pathogenic variants in genes that result in sarcomere dysfunction. The condition occurs in approximately 1 in 500 individuals.
Ventricular hypertrophy may also be a presenting feature of a systemic genetic disorder and should be distinguished from sarcomeric HCM. TTR-related cardiac amyloidosis is characterized by progressive LVH and restrictive cardiomyopathy with or without peripheral neuropathy; the age of onset is typically in the sixth decade of life. Danon disease is characterized by cardiomyopathy in addition to myopathy and varying intellectual disability. Fabry disease is a lysosomal storage disease that presents variably depending on residual enzyme activity, though may be the underlying diagnosis in unexplained LVH in adults. Pompe disease is a glycogen storage disorder associated with cardiomyopathy; the severity of disease is variable, and additional features can include proximal muscular weakness and respiratory insufficiency. Noonan syndrome may be suspected in individuals with characteristic facies, short stature, variable development delay, and congenital heart disease.8 Mitochondrial cardiomyopathies may result in isolated cardiomyopathy or present with various organ system involvement.
A genetic diagnosis may have implications for treatment, management, recurrence risk, and family member testing.