Neutral Lipid Storage Disease with Myopathy via the PNPLA2 Gene
Summary and Pricing
Test Method
Exome Sequencing with CNV DetectionTest Code | Test Copy Genes | Test CPT Code | Gene CPT Codes Copy CPT Code | Base Price | |
---|---|---|---|---|---|
11595 | PNPLA2 | 81479 | 81479,81479 | $990 | Order Options and Pricing |
Pricing Comments
Our favored testing approach is exome based NextGen sequencing with CNV analysis. This will allow cost effective reflexing to PGxome or other exome based tests. However, if full gene Sanger sequencing is desired for STAT turnaround time, insurance, or other reasons, please see link below for Test Code, pricing, and turnaround time information. If the Sanger option is selected, CNV detection may be ordered through Test #600.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
Click here for costs to reflex to whole PGxome (if original test is on PGxome Sequencing platform).
Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing platform).
The Sanger Sequencing method for this test is NY State approved.
For Sanger Sequencing click here.Turnaround Time
3 weeks on average for standard orders or 2 weeks on average for STAT orders.
Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.
Targeted Testing
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
Clinical Features and Genetics
Clinical Features
Neutral lipid storage disease with myopathy (NLSDM, OMIM 610717) is characterized by the accumulation of cytoplasmic lipid droplets in a wide range of cells types, including muscle cells and blood granulocytes; the absence of skin findings; and the presence of mild myopathy. NLSDM is typically a slowly progressive myopathy with onset around the third decade of life. Cardiomyopathy, as a finding later in the disease course, is common in NLSDM. Muscle weakness is most notable in the shoulder girdle and less so in the pelvic girdle and distal muscle groups. Patients exhibit exercise intolerance and highly elevated serum CpK levels. Muscle biopsies reveal massive accumulation of neutral lipid droplets, while peripheral blood smears exhibit persistent vacuoles in the cytoplasm of granulocytes (Reilich et al. J Neurol 258:1987-1997, 2011; Campagna et al. Biochem Biophys Res Commun 377:843-846, 2008). Rimmed vacuoles in muscle fibers have also been noted in one case of NLSDM (Chen et al. Clin Neuropathol 29:351-366, 2010). Although myopathy associated with NLSDM is generally considered to be mild, one case of severe myopathy in NLSDM was reported, in which a homozygous truncating variant affecting the adipose triglyceride lipase active site was found (Akiyama et al. Muscle Nerve 36:856-859, 2007).
Genetics
Neutral lipid storage disease with myopathy is inherited as an autosomal recessive disorder. The only gene known to be associated with this disorder is the adipose triglyceride lipase gene (PNPLA2, OMIM 609059; Fischer et al. Nat Genet 39:28-30, 2007). PNPLA2 (patatin-like phospholipase domain-containing protein 2) encodes adipose triglyceride lipase, the enzyme that catalyzes the rate-limiting step of lipolysis. Most NLSDM-causing variants of the PNPLA2 gene are small deletions resulting in loss of function.
Adipose triglyceride lipase is coded by exons 2-10 of the PNPLA2 gene on chromosome 11p15.
Clinical Sensitivity - Sequencing with CNV PGxome
Clinical sensitivity should be high in patients meeting clinical and histological criteria for this disorder. Analytical sensitivity should also be high because nearly all reported PNPLA2 variants are detectable by direct sequencing of genomic DNA.
Testing Strategy
This test provides full coverage of all coding exons of the PNPLA2 gene plus 10 bases of flanking noncoding DNA in all available transcripts along with other non-coding regions in which pathogenic variants have been identified at PreventionGenetics or reported elsewhere. We define full coverage as >20X NGS reads or Sanger sequencing. PGnome panels typically provide slightly increased coverage over the PGxome equivalent. PGnome sequencing panels have the added benefit of additional analysis and reporting of deep intronic regions (where applicable).
Dependent on the sequencing backbone selected for this testing, discounted reflex testing to any other similar backbone-based test is available (i.e., PGxome panel to whole PGxome; PGnome panel to whole PGnome).
Indications for Test
Patients with shoulder and pelvic girdle muscle weakness beginning in their 30s with intracellular accumulation of neutral lipids. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in PNPLA2.
Gene
Official Gene Symbol | OMIM ID |
---|---|
PNPLA2 | 609059 |
Inheritance | Abbreviation |
---|---|
Autosomal Dominant | AD |
Autosomal Recessive | AR |
X-Linked | XL |
Mitochondrial | MT |
Disease
Name | Inheritance | OMIM ID |
---|---|---|
Neutral Lipid Storage Disease With Myopathy | AR | 610717 |
Citations
- Akiyama, M., et.al. (2007). "Novel duplication mutation in the patatin domain of adipose triglyceride lipase (PNPLA2) in neutral lipid storage disease with severe myopathy." Muscle Nerve 36(6): 856-9. PubMed ID: 17657808
- Campagna, F., et.al. (2008). "Novel mutations in the adipose triglyceride lipase gene causing neutral lipid storage disease with myopathy." Biochem Biophys Res Commun 377(3): 843-6. PubMed ID: 18952067
- Chen, J., et.al. (2010). "A novel PNPLA2 mutation causes neutral lipid storage disease with myopathy (NLSDM) presenting muscular dystrophic features with lipid storage and rimmed vacuoles." Clin Neuropathol 29(6): 351-6. PubMed ID: 21073837
- Fischer, J., et.al. (2007). "The gene encoding adipose triglyceride lipase (PNPLA2) is mutated in neutral lipid storage disease with myopathy." Nat Genet 39(1): 28-30. PubMed ID: 17187067
- Reilich, P., et.al. (2011). "The phenotypic spectrum of neutral lipid storage myopathy due to mutations in the PNPLA2 gene." J Neurol 258(11): 1987-97. PubMed ID: 21544567
Ordering/Specimens
Ordering Options
We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.
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.
- PGnome sequencing panels can be ordered via the myPrevent portal only at this time.
Requisition Form
- A completed requisition form must accompany all specimens.
- Billing information along with specimen and shipping instructions are within the requisition form.
- All testing must be ordered by a qualified healthcare provider.
For Requisition Forms, visit our Forms page
If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.
Specimen Types
Specimen Requirements and Shipping Details
PGxome (Exome) Sequencing Panel
PGnome (Genome) Sequencing Panel
ORDER OPTIONS
View Ordering Instructions1) Select Test Type
2) Select Additional Test Options
No Additional Test Options are available for this test.