Left Ventricular Noncompaction (LVNC) Sequencing Panel
- Summary and Pricing
- Clinical Features and Genetics
|Test Code||Test||CPT Code Copy CPT Codes|
|Full Panel Price*||$1540.00|
|Test Code||Test||Total Price||CPT Codes Copy CPT Codes|
|1333||Genes x (9)||$1540.00||81405, 81406(x4), 81407(x2), 81479(x2)||Add|
If you would like to order a subset of these genes contact us to discuss pricing.
For ordering targeted known variants, please proceed to our Targeted Variants landing page.
The great majority of tests are completed within 28 days.
Up to 20-30% of adults with LVNC are expected to have a pathogenic mutation in one of the genes in this panel (Ichida et al 2001; Vatta et al. 2003; Hermida-Prieto et al. 2004; Klaassen et al. 2008; Hoedemaekers et al. 2010).
Deletion/Duplication Testing via aCGH
|Test Code||Test||Individual Gene Price||CPT Code Copy CPT Codes|
|Full Panel Price*||$840.00|
|Test Code||Test||Total Price||CPT Codes Copy CPT Codes|
|600||Genes x (9)||$840.00||81479(x9)||Add|
# of Genes Ordered
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The great majority of tests are completed within 28 days.
Very few gross deletions, duplications and complex rearrangements have been reported in patients with LVNC. Gross deletions and/or complex rearrangements have been reported in LMNA, MYBPC3, MYH7 and TAZ.
Left Ventricular Noncompaction (LVNC) cardiomyopathy is a heart condition believed to result from an arrest in cardiac development during embryogenesis, resulting in a spongy, noncompacted appearance. The numerous trabeculations are most pronounced in the left ventricle (Chin et al. 1990). Diagnosis is based on structural features using echocardiography and cardiac MRI. LVNC can occur in isolation or be found with other heart defects (most commonly dilated cardiomyopathy, hypertrophic cardiomyopathy, and/or congenital heart defects), genetic syndromes (such as Barth syndrome), and neuromuscular disorders (Pignatelli et al. 2003; Wald et al 2004; Oechslin et al. 2011; Jefferies 2013). Prevalence of LVNC is estimated to be ~0.25% of adults referred for echocardiography (Sandhu et al. 2008). Eighteen to fifty percent of isolated LVNC cases in adults are believed to be familial (Hoedemaekers et al. 2010).
LVNC is a genetically heterogeneous disorder that is inherited in an autosomal dominant (ACTC1, DTNA, LDB3, LMNA, MYBPC3, MYH7, TNNT2, VCL) or X-linked recessive (TAZ) manner (Ichida et al 2001; Vatta et al. 2003; Hermida-Prieto et al. 2004; Klaassen et al. 2008; Hoedemaekers et al. 2010). Mutations in TAZ causes Barth syndrome, which can have LVNC as one of the symptoms. See individual gene test descriptions for information on molecular biology of gene products.
For this NextGen panel, we sequence all coding exons of the genes listed below, plus ~20 nucleotides of flanking DNA for each exon. Sequencing is accomplished by capturing specific regions with an optimized solution-based hybridization kit, followed by massively parallel sequencing of the captured DNA fragments. Additional Sanger sequencing is performed for any regions not captured or with insufficient number of sequence reads. All pathogenic and undocumented variants are confirmed by Sanger sequencing.
Indications for Test
Individuals with LVNC.
|Official Gene Symbol||OMIM ID|
- Genetic Counselor Team - firstname.lastname@example.org
- Guoli Sun, MD, PhD, FACMG - email@example.com
- Chin TK, Perloff JK, Williams RG, Jue K, Mohrmann R. 1990. Isolated noncompaction of left ventricular myocardium. A study of eight cases. Circulation 82: 507–513. PubMed ID: 2372897
- Hermida-Prieto et al. (2004) Familial dilated cardiomyopathy and isolated left ventricular noncompaction associated with lamin A/C gene mutations. Am J Cardiol. 94:50-4 PubMed ID: 15219508
- Hoedemaekers et al. 2010. The Importance of Genetic Counseling, DNA Diagnostics, and Cardiologic Family Screening in Left Ventricular Noncompaction Cardiomyopathy. Circulation: Cardiovascular Genetics 3: 232–239. PubMed ID: 20530761
- Ichida et al. (2001) Novel gene mutations in patients with left ventricular noncompaction or Barth syndrome. Circulation. 103:1256-63 PubMed ID: 11238270
- Jefferies JL. 2013. Barth syndrome. American Journal of Medical Genetics Part C: Seminars in Medical Genetics 163: 198–205. PubMed ID: 23843353
- Klaassen et al. (2008) Mutations in sarcomere protein genes in left ventricular noncompaction. Circulation. 117:2893-901 PubMed ID: 18506004
- Oechslin E, Jenni R. 2011. Left ventricular non-compaction revisited: a distinct phenotype with genetic heterogeneity? European Heart Journal 32: 1446–1456. PubMed ID: 21285074
- Pignatelli et al. 2003. Clinical Characterization of Left Ventricular Noncompaction in Children: A Relatively Common Form of Cardiomyopathy. Circulation 108: 2672–2678. PubMed ID: 14623814
- Sandhu et al. 2008. Prevalence and characteristics of left ventricular noncompaction in a community hospital cohort of patients with systolic dysfunction. Echocardiography 25:8-10. PubMed ID: 18186774
- Vatta et al. (2003) Mutations in Cypher/ZASP in patients with dilated cardiomyopathy and left ventricular non-compaction. J Am Coll Cardiol. 42:2014-27 PubMed ID: 14662268
- Wald et al. 2004. Determinants of outcome in isolated ventricular noncompaction in childhood. Am J Cardiol 94:1581-4 PubMed ID: 15589025
We use a combination of Next Generation Sequencing (NGS) and Sanger sequencing technologies to cover the full coding regions of the listed genes plus ~20 bases of non-coding DNA flanking each exon. As required, genomic DNA is extracted from the patient specimen. For NGS, patient DNA corresponding to these regions is captured using an optimized set of DNA hybridization probes. Captured DNA is sequenced using Illumina’s Reversible Dye Terminator (RDT) platform (Illumina, San Diego, CA, USA). Regions with insufficient coverage by NGS are covered by Sanger sequencing. All pathogenic, likely pathogenic, or variants of uncertain significance are confirmed by Sanger sequencing.
For Sanger sequencing, Polymerase Chain Reaction (PCR) is used to amplify targeted regions. After purification of the PCR products, cycle sequencing is carried out using the ABI Big Dye Terminator v.3.0 kit. PCR products are resolved by electrophoresis on an ABI 3730xl capillary sequencer. In nearly all cases, cycle sequencing is performed separately in both the forward and reverse directions.
Patient DNA sequence is aligned to the genomic reference sequence for the indicated gene region(s). All differences from the reference sequences (sequence variants) are assigned to one of five interpretation categories, listed below, per ACMG Guidelines (Richards et al. 2015).
(1) Pathogenic Variants
(2) Likely Pathogenic Variants
(3) Variants of Uncertain Significance
(4) Likely Benign Variants
(5) Benign, Common Variants
Human Genome Variation Society (HGVS) recommendations are used to describe sequence variants (http://www.hgvs.org). Rare variants and undocumented variants are nearly always classified as likely benign if there is no indication that they alter protein sequence or disrupt splicing.
As of March 2016, 6.36 Mb of sequence (83 genes, 1557 exons) generated in our lab was compared between Sanger and NextGen methodologies. We detected no differences between the two methods. The comparison involved 6400 total sequence variants (differences from the reference sequences). Of these, 6144 were nucleotide substitutions and 256 were insertions or deletions. About 65% of the variants were heterozygous and 35% homozygous. The insertions and deletions ranged in length from 1 to over 100 nucleotides.
In silico validation of insertions and deletions in 20 replicates of 5 genes was also performed. The validation included insertions and deletions of lengths between 1 and 100 nucleotides. Insertions tested in silico: 2200 between 1 and 5 nucleotides, 625 between 6 and 10 nucleotides, 29 between 11 and 20 nucleotides, 25 between 21 and 49 nucleotides, and 23 at or greater than 50 nucleotides, with the largest at 98 nucleotides. All insertions were detected. Deletions tested in silico: 1813 between 1 and 5 nucleotides, 97 between 6 and 10 nucleotides, 32 between 11 and 20 nucleotides, 20 between 21 and 49 nucleotides, and 39 at or greater than 50 nucleotides, with the largest at 96 nucleotides. All deletions less than 50 nucleotides in length were detected, 13 greater than 50 nucleotides in length were missed. Our standard NextGen sequence variant calling algorithms are generally not capable of detecting insertions (duplications) or heterozygous deletions greater than 100 nucleotides. Large homozygous deletions appear to be detectable.
Interpretation of the test results is limited by the information that is currently available. Better interpretation should be possible in the future as more data and knowledge about human genetics and this specific disorder are accumulated.
When Sanger sequencing does not reveal any difference from the reference sequence, or when a sequence variant is homozygous, we cannot be certain that we were able to detect both patient alleles. Occasionally, a patient may carry an allele which does not amplify, due to a large deletion or insertion. In these cases, the report will contain no information about the second allele. Our Sanger and NGS Sequencing tests are generally not capable of detecting Copy Number Variants (CNVs).
We sequence all coding exons for each given transcript, plus ~20 bp of flanking non-coding DNA for each exon. Test reports contain no information about other portions of the gene, such as regulatory domains, deep intronic regions or any currently uncharacterized alternative exons.
In most cases, we are unable to determine the phase of sequence variants. In particular, when we find two likely causative mutations for recessive disorders, we cannot be certain that the mutations are on different alleles.
Our ability to detect minor sequence variants due to somatic mosaicism is limited. Sequence variants that are present in less than 50% of the patient’s nucleated cells may not be detected.
Runs of mononucleotide repeats (eg (A)n or (T)n) with n >8 in the reference sequence are generally not analyzed because of strand slippage during PCR.
Unless otherwise indicated, DNA sequence data is obtained from a specific cell-type (usually leukocytes from whole blood). Test reports contain no information about the DNA sequence in other cell-types.
We cannot be certain that the reference sequences are correct.
Rare, low probability interpretations of sequencing results, such as for example the occurrence of de novo mutations in recessive disorders, are generally not included in the reports.
We have confidence in our ability to track a specimen once it has been received by PreventionGenetics. However, we take no responsibility for any specimen labeling errors that occur before the sample arrives at PreventionGenetics.
Deletion/Duplication Testing Via Array Comparative Genomic Hybridization
Equal amounts of genomic DNA from the patient and a gender matched reference sample are amplified and labeled with Cy3 and Cy5 dyes, respectively. To prevent any sample cross contamination, a unique sample tracking control is added into each patient sample. Each labeled patient product is then purified, quantified, and combined with the same amount of reference product. The combined sample is loaded onto the designed array and hybridized for at least 22-42 hours at 65°C. Arrays are then washed and scanned immediately with 2.5 µM resolution. Only data for the gene(s) of interest for each patient are extracted and analyzed.
PreventionGenetics' high density gene-centric custom designed aCGH enables the detection of relatively small deletions and duplications within a single exon of a given gene or deletions and duplications encompassing the entire gene. PreventionGenetics has established and verified this test's accuracy and precision.
Our dense probe coverage may allow detection of deletions/duplications down to 100 bp; however due to limitations and probe spacing this cannot be guaranteed across all exons of all genes. Therefore, some copy number changes smaller than 100-300 bp within a targeted large exon may not be detected by our array.
This array may not detect deletions and duplications present at low levels of mosaicism or those present in genes that have pseudogene copies or repeats elsewhere in the genome.
aCGH will not detect balanced translocations, inversions, or point mutations that may be responsible for the clinical phenotype.
Breakpoints, if occurring outside the targeted gene, may be hard to define.
The sensitivity of this assay may be reduced when DNA is extracted by an outside laboratory.
myPrevent - Online Ordering
- The test can be added to your online orders in the Summary and Pricing section.
- Once the test has been added log in to myPrevent to fill out an online requisition form.
- The first four pages of the requisition form must accompany all specimens.
- Billing information is on the third and fourth pages.
- Specimen and shipping instructions are listed on the fifth and sixth pages.
- All testing must be ordered by a qualified healthcare provider.
(Delivery accepted Monday - Saturday)
- Collect 3-5 ml (5 ml preferred) of whole blood in EDTA (purple top tube) or ACD (yellow top tube). For Test #500-DNA Banking only, collect 10-20 ml of whole blood.
- For small babies, we require a minimum of 1 ml of blood.
- Only one blood tube is required for multiple tests.
- Ship blood tubes at room temperature in an insulated container. Do not freeze blood.
- During hot weather, include a frozen ice pack in the shipping container. Place a paper towel or other thin material between the ice pack and the blood tube.
- In cold weather, include an unfrozen ice pack in the shipping container as insulation.
- At room temperature, blood specimen is good for up to 48 hours.
- If refrigerated, blood specimen is good for up to one week.
- Label the tube with the patient name, date of birth and/or ID number.
(Delivery accepted Monday - Saturday)
- NextGen Sequencing Tests: Send in screw cap tube at least 10 µg of purified DNA at a concentration of at least 50 µg/ml
- Sanger Sequencing Tests: Send in a screw cap tube at least 15 µg of purified DNA at a concentration of at least 20 µg/ml. For tests involving the sequencing of more than three genes, send an additional 5 µg DNA per gene. DNA may be shipped at room temperature.
- Deletion/Duplication via aCGH: Send in screw cap tube at least 1 µg of purified DNA at a concentration of at least 100 µg/ml.
- Whole-Genome Chromosomal Microarray: Collect at least 5 µg of DNA in TE (10 mM Tris-cl pH 8.0, 1mM EDTA), dissolved in 200 µl at a concentration of at least 100 ng/ul (indicate concentration on tube label). DNA extracted using a column-based method (Qiagen) or bead-based technology is preferred.
(Delivery accepted Monday - Thursday)
- PreventionGenetics should be notified in advance of arrival of a cell culture.
- Ship at least two T25 flasks of confluent cells.
- Label the flasks with the patient name, date of birth, and/or ID number.
- We do not culture cells.