DNA icon

Steroid-Resistant Nephrotic Syndrome and Coenzyme Q10 Deficiency via the COQ2 Gene

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
8601 COQ2 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
8601COQ281479 81479,81479 $890 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 backbone).

Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing backbone).

The Sanger Sequencing method for this test is NY State approved.

For Sanger Sequencing click here.

Turnaround Time

18 days on average for standard orders or 13 days 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.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Angela Gruber, PhD

Clinical Features and Genetics

Clinical Features

Nephrotic syndrome is a genetically heterogeneous disease defined by proteinuria, hypoalbuminemia, hyperlipidemia, and edema (Benoit et al. 2010; Santín et al. 2011; Saleem 2012). Approximately 20% of cases are steroid-resistant nephrotic syndrome (SRNS), characterized by resistance to steroid treatment and rapid progression to end-stage renal failure. The prevalent histological feature of SRNS is focal segmental glomerulosclerosis (FSGS), which has been seen in approximately 60% of SRNS cases. Diffuse mesangial sclerosis (DMS) is the other important histological feature associated with SRNS. The clinical courses of SRNS vary greatly with a wide range of age at onset from birth to adulthood.

Coenzyme Q10 deficiency is primarily characterized by neurological and muscular symptoms and has been associated with three main clinical phenotypes: a predominantly myopathic form with central nervous system involvement, an infantile encephalomyopathy with renal dysfunction, and an ataxic form with cerebellar atrophy (Quinzii et al. 2006; Desbats et al. 2015).

Recessive mutations in the COQ2 gene can cause a primary glomerular disease (COQ2 nephropathy), including early-onset SRNS, with variable renal lesions through coenzyme Q10 deficiency (Diomedi-Camassei et al. 2007).

Genetics

COQ2-associated coenzyme Q10 deficiency is an autosomal recessive disorder (Quinzii et al. 2006; Diomedi-Camassei et al. 2007). The COQ2 gene (7 coding exons) encodes para-hydroxybenzoate-polyprenyl transferase in the coenzyme Q10 synthesis pathway. Genetic defects documented to date in COQ2 only include missense, nonsense variants and small indels (Human Gene Mutation Database).

All proteins encoded by SRNS-associated genes are localized to the podocytes, which are essential in maintaining the glomerular filtration barrier. Regarding protein function and location in podocytes, COQ2 belongs to mitochondrial proteins (Malaga-Dieguez et al. 2013).

Clinical Sensitivity - Sequencing with CNV PGxome

Detection rate of pathogenic variants in the COQ2 gene in a large cohort of patients with coenzyme Q10 deficiency is unknown in the literature because documented COQ2 pathogenic variants have been reported only in limited cases. Analytical sensitivity should be high, as all reported mutations are detectable by sequencing.

Testing Strategy

This test provides full coverage of all coding exons of the COQ2 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

Candidates for this test are patients with coenzyme Q10 deficiency. Testing is also indicated for family members of patients who have known pathogenic variants in the COQ2 gene. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in COQ2.

Gene

Official Gene Symbol OMIM ID
COQ2 609825
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Coenzyme Q10 Deficiency AR 607426

Related Test

Name
Coenzyme Q10 Ubiquinone Deficiency Panel

Citations

  • Benoit G. et al. 2010. Pediatric Nephrology (berlin, Germany). 25: 1621-32. PubMed ID: 20333530
  • Desbats MA, Lunardi G, Doimo M, Trevisson E, Salviati L. 2015. Genetic bases and clinical manifestations of coenzyme Q10 (CoQ 10) deficiency. J. Inherit. Metab. Dis. 38: 145–156. PubMed ID: 25091424
  • Diomedi-Camassei F, Giandomenico S Di, Santorelli FM, Caridi G, Piemonte F, Montini G, Ghiggeri GM, Murer L, Barisoni L, Pastore A, Muda AO, Valente ML, Bertini E, Emma F. 2007. COQ2 nephropathy: a newly described inherited mitochondriopathy with primary renal involvement. J. Am. Soc. Nephrol. 18: 2773–2780. PubMed ID: 17855635
  • Human Gene Mutation Database (Bio-base).
  • Malaga-Dieguez L, Susztak K. 2013. ADCK4 “reenergizes” nephrotic syndrome. J. Clin. Invest. 123: 4996–4999. PubMed ID: 24270414
  • Quinzii C, Naini A, Salviati L, Trevisson E, Navas P, Dimauro S, Hirano M. 2006. A mutation in para-hydroxybenzoate-polyprenyl transferase (COQ2) causes primary coenzyme Q10 deficiency. Am. J. Hum. Genet. 78: 345–349. PubMed ID: 16400613
  • Saleem M.A. 2013. Pediatric Nephrology (berlin, Germany). 28: 699-709. PubMed ID: 22782578
  • Santín S. et al. 2011. Clinical Journal of the American Society of Nephrology : Cjasn. 6: 1139-48. PubMed ID: 21415313

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


Specimen Types

Specimen Requirements and Shipping Details

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

loading Loading... ×

ORDER OPTIONS

View Ordering Instructions

1) Select Test Method (Backbone)


1) Select Test Type


2) Select Additional Test Options

STAT and Prenatal Test Options are not available with Patient Plus.

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
Total Price: $
×
Copy Text to Clipboard
×