3-Methylcrotonyl-CoA Carboxylase Deficiency via the MCCC2 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 | |
---|---|---|---|---|---|
11839 | MCCC2 | 81406 | 81406,81479 | $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
3-methylcrotonyl-CoA carboxylase (MCC) deficiency (OMIM 210200 and 210210) is a defect in the catabolism of the amino acid leucine. MCC is the next enzyme after isovaleryl-CoA dehydrogenase in the degradation pathway. MCC deficiency leads to abnormally high levels of 3-methylcrotonylglycine in the urine and 3- hydroxyisovalerylcarnitine in the blood. MCC deficiency is one of the most frequent disorders detected through neonatal screening with tandem mass spectrometry. The most severe forms of MCC deficiency have onset in infancy and are characterized by episodes of vomiting, lethargy, and muscle weakness. These episodes can lead to seizures, coma, and death. A variety of other, mostly neurological, symptoms have been reported.
Genetics
3-methylcrotonyl-CoA carboxylase (MCC) deficiency is an autosomal recessive disorder. The MCC enzyme has two subunits, α and β, encoded by the MCCC1 (also called MCCA) and MCCC2 (MCCB) genes, respectively. Variants in either gene can lead to MCC deficiency. No differences in clinical features have been reported for variants in MCCC1 versus MCCC2. About 30 different causative variants have been reported in MCCC1 and 45 in MCCC2 (Gallardo et al. Am J Hum Genet 68:334-346, 2001; Baumgartner et al. J Clin Invest 107:495-504, 2001; Dantas et al. Hum Mut 26:164, 2005; Stadler et al. Hum Mut 27:748-59,2006). In both genes, the causative variants are about equally split between missense and nonsense/frameshift/splicing. No common variants have been reported. Variants are distributed throughout the lengths of the genes. Although nearly all MCC deficiency patients detected by neonatal screening carry likely causative variants, it appears that many such patients, perhaps even the great majority, will not experience significant health problems (Dantas et al. 2005; Stadler et al. 2006). The genetic or non-genetic factors which exert such strong control over the expressivity of the variants are currently unknown.
Clinical Sensitivity - Sequencing with CNV PGxome
Stadler et al. 2006 reported detecting two causative variants by sequencing the MCCC1 and MCCC2 genes in 28 out of 28 patients.
Testing Strategy
This test provides full coverage of all coding exons of the MCCC2 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
All MCC deficiency patients are candidates for this test. In cases where DNA from an affected child is unavailable, we will sequence the genes in parents or other family members. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in MCCC2.
All MCC deficiency patients are candidates for this test. In cases where DNA from an affected child is unavailable, we will sequence the genes in parents or other family members. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in MCCC2.
Gene
Official Gene Symbol | OMIM ID |
---|---|
MCCC2 | 609014 |
Inheritance | Abbreviation |
---|---|
Autosomal Dominant | AD |
Autosomal Recessive | AR |
X-Linked | XL |
Mitochondrial | MT |
Disease
Name | Inheritance | OMIM ID |
---|---|---|
3-Methylcrotonyl CoA Carboxylase 2 Deficiency | AR | 210210 |
Citations
- Baumgartner, M. R., et.al. (2001). "The molecular basis of human 3-methylcrotonyl-CoA carboxylase deficiency." J Clin Invest 107(4): 495-504. PubMed ID: 11181649
- Dantas, M. F., et.al. (2005). "3-Methylcrotonyl-CoA carboxylase deficiency: mutation analysis in 28 probands, 9 symptomatic and 19 detected by newborn screening." Hum Mutat 26(2): 164. PubMed ID: 16010683
- Gallardo, M. E., et.al. (2001). "The molecular basis of 3-methylcrotonylglycinuria, a disorder of leucine catabolism." Am J Hum Genet 68(2): 334-46. PubMed ID: 11170888
- Stadler, S. C., et.al. (2006). "Newborn screening for 3-methylcrotonyl-CoA carboxylase deficiency: population heterogeneity of MCCA and MCCB mutations and impact on risk assessment." Hum Mutat 27(8): 748-59. PubMed ID: 16835865
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.