Surfactant Protein C Deficiency via the SFTPC 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
8697 SFTPC 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
8697SFTPC81479 81479(x2) $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

  • Fang Xu, PhD, FACMG

Clinical Features and Genetics

Clinical Features

Surfactant Protein C (SP-C) deficiency is a respiratory disorder due to dysfunction of surfactant composition. Surfactant is a lipid and protein mixture lining the lung tissue that lowers alveolar surface tension and prevents atelectasis during expiration. Loss of surfactant function results in alveoli collapse following expiration leading to shortness of breath and impaired oxygen delivery in the lung. Patients with SP-C deficiency have variable clinical presentation from lethal disease via respiratory failure in infancy to asymptomatic (Thomas et al. 2002; Hamvas 2006). Adult forms present with idiopathic interstitial pneumonias and pulmonary fibrosis (van Moorsel et al. 2010; Gower and Nogee 2011). Genetic testing is helpful in the differential diagnosis of SP-B deficiency from other surfactant deficiencies, non-bacterial pneumonitis, chemical/inhalant pneumonitis, chronic aspiration, and immunologically mediated lung disease (Hamvas 2006).

Genetics

SP-C deficiency in inherited in an autosomal dominant manner through pathogenic variants in the SFTPC gene. Surfactant dysfunction may also be inherited in an autosomal dominant manner through pathogenic variants in NKX2-1 or an autosomal recessive manner through pathogenic variants in the SFTPB and ABCA3 genes (Hamvas 2006; Weaver and Conkright 2001). SP-C deficiency onset and clinical features are variable within families even when presenting with the same pathogenic variant. This is thought to be due to environmental and other genetic modifiers that influence presentation of SP-C Deficiency (Thomas et al. 2002). Nearly 50% of cases of SP-C deficiency have de novo pathogenic variants in the SFTPC gene. Missense variants account for the majority of pathogenic variants, occur within the linker and BRIOCHOS domains and disrupt intracellular trafficking of the SFTPC protein (Thurm et al. 2013; Willander et al. 2012; Sáenz et al. 2015). The c.218T>C (p.Ile73Thr) variant is the most common pathogenic variant and is found in about a quarter of cases of SP-C deficiency. Splice site and small insertions/deletions have also been reported in patients with SP-C deficiency (Hamvas 2006). The SFTPC gene encodes surfactant protein C, an integral membrane protein. Surfactant protein C is initially produced as a pro-peptide requiring proteolytic processing prior to insertion in the cell membrane. Surfactant protein C aids in lowering alveolar surface tension to prevent atelectasis (Weaver and Conkright 2001).

Clinical Sensitivity - Sequencing with CNV PGxome

Clinical sensitivity is currently unknown as only a small number of patients have been reported with SP-C deficiency. Analytical sensitivity is high as all reported pathogenic variants to date are detectable by sequencing.

Testing Strategy

This test provides full coverage of all coding exons of the SFTPC 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 testing include individuals with histopathology, radiography and symptoms indicative of interstitial lung disease. Common symptoms in children with SP-C deficiency include cough, tachypnea, and hypoxemia (Hamvas 2006).

Gene

Official Gene Symbol OMIM ID
SFTPC 178620
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Disease

Name Inheritance OMIM ID
Surfactant Metabolism Dysfunction, Pulmonary, 2 AD 610913

Related Tests

Name
Interstitial Lung Disease Panel
Pulmonary Fibrosis and Surfactant Dysfunction Disorders Panel

Citations

  • Gower WA, Nogee LM. 2011. Paediatric Respiratory Reviews. 12: 223-9. PubMed ID: 22018035
  • Hamvas A. 2006. Seminars in Perinatology. 30: 316-26. PubMed ID: 17142157
  • Sáenz A et al. 2015. The Journal of Biological Chemistry. 290: 17628-41. PubMed ID: 26041777
  • Thomas AQ et al. 2002. American Journal of Respiratory and Critical Care Medicine. 165: 1322-8. PubMed ID: 11991887
  • Thurm T et al. 2013. European Journal of Clinical Investigation. 43: 791-800. PubMed ID: 23701443
  • van Moorsel CH et al. 2010. American Journal of Respiratory and Critical Care Medicine. 182: 1419-25. PubMed ID: 20656946
  • Weaver TE, Conkright JJ. 2001. Annual Review of Physiology. 63: 555-78. PubMed ID: 11181967
  • Willander H et al. 2012. Proceedings of the National Academy of Sciences of the United States of America. 109: 2325-9. PubMed ID: 22308375

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

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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: $
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