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Saethre-Chotzen Syndrome via the TWIST1 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
TWIST1 81404 81404,81403 $990
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
9213TWIST181404 81404,81403 $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.

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.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Stela Berisha, PhD, FACMG

Clinical Features and Genetics

Clinical Features

Saethre-Chotzen syndrome is characterized by coronal synostosis, facial asymmetry, ptosis, and small ears with prominent crus syndactyly. Less common feature include short stature, parietal foramina, vertebral fusions, radioulnar synostosis, cleft palate, maxillary hypoplasia, ocular hypertelorism, hallux valgus, duplicated distal hallucal phalanx, and congenital heart malformations. The prevalence is ~1:25,000 to 1:50,000 (Gallagher et al. 2012). TWIST1 pathogenic variants also cause Baller-Gerold syndrome, craniosynostosis type1, Robinow-Sorauf syndrome, and Saethre-Chotzen syndrome with eyelid anomalies.

Genetics

Saethre-Chotzen syndrome is inherited in an autosomal dominant manner. Many Saethre-Chotzen syndrome cases have an affected parent (Gallagher et al. 2012). De novo pathogenic variants were seen in 1/3 of the tested patients (Kress et al. 2006; Human Gene Mutation Database).The TWIST1 protein coded by the TWIST1 gene is a transcription factor in the helix-loop-helix family which regulates embryonic development of many organs. Currently, ~170 unique TWIST1 pathogenic variants have been reported. They are: missense (34%), nonsense: (15%), small deletion/insertions (32%), large deletions (11%), and translocation/inversions (6%) (Johnson et al. 1998; Kress et al. 2006; Human Gene Mutation Database).

Clinical Sensitivity - Sequencing with CNV PGxome

TWIST1 pathogenic variants were identified in 39 out of 124 unrelated families with coronal suture synostosis (Kress et al 2006). 7 out of the 39 patients had an entire TWIST1 gene deletion, while 32 out of the 39 patients had missense, nonsense and small deletions (Kress et al 2006; Human Gene Mutation Database).

Testing Strategy

This test provides full coverage of all coding exons of the TWIST1 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 symptoms consistent with Saethre-Chotzen syndrome, Baller-Gerold syndrome, Baller-Gerold syndrome, craniosynostosis type1, Robinow-Sorauf syndromeand, and Saethre-Chotzen syndrome with eyelid anomalies and the family members of patients who have known TWIST1 pathogenic variants.

Gene

Official Gene Symbol OMIM ID
TWIST1 601622
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Related Tests

Name
Achondroplasia via the FGFR3 Gene, Exon 10
Craniofrontonasal Syndrome via the EFNB1 Gene
Craniosynostosis and Dental Anomalies, Autosomal Recessive Crouzon-like Craniosynostosis via the IL11RA Gene
Craniosynostosis via the MSX2 Gene
Frontonasal Dysplasia (Frontorhiny) via the ALX3 Gene

Citations

  • Gallagher ER, Ratisoontorn C, Cunningham ML. 2012. Saethre-Chotzen Syndrome. In: Pagon RA, Adam MP, Ardinger HH, Wallace SE, Amemiya A, Bean LJ, Bird TD, Dolan CR, Fong C-T, Smith RJ, and Stephens K, editors. GeneReviews(®), Seattle (WA): University of Washington, Seattle. PubMed ID: 20301368
  • Gallagher ER, Ratisoontorn C, Cunningham ML. 2012. Saethre-Chotzen Syndrome. In: Pagon RA, Adam MP, Ardinger HH, Wallace SE, Amemiya A, Bean LJ, Bird TD, Dolan CR, Fong C-T, Smith RJ, and Stephens K, editors. GeneReviews(®), Seattle (WA): University of Washington, Seattle. PubMed ID: 20301368
  • Human Gene Mutation Database (Bio-base).
  • Human Gene Mutation Database.
  • Johnson D, Horsley SW, Moloney DM, Oldridge M, Twigg SR, Walsh S, Barrow M, Njølstad PR, Kunz J, Ashworth GJ, Wall SA, Kearney L, Wilkie AO. 1998. A comprehensive screen for TWIST mutations in patients with craniosynostosis identifies a new microdeletion syndrome of chromosome band 7p21.1. Am J Hum Genet 63: 1282-1293. PubMed ID: 9792856
  • Kress W, Schropp C, Lieb G, Petersen B, Büsse-Ratzka M, Kunz J, Reinhart E, Schäfer W-D, Sold J, Hoppe F, Pahnke J, Trusen A, Sörensen N, Krauss J. 2006. Saethre-Chotzen syndrome caused by TWIST 1 gene mutations: functional differentiation from Muenke coronal synostosis syndrome. Eur. J. Hum. Genet. 14: 39-48. PubMed ID: 16251895
  • Kress W, Schropp C, Lieb G, Petersen B, Büsse-Ratzka M, Kunz J, Reinhart E, Schäfer W-D, Sold J, Hoppe F, Pahnke J, Trusen A, Sörensen N, Krauss J. 2006. Saethre-Chotzen syndrome caused by TWIST 1 gene mutations: functional differentiation from Muenke coronal synostosis syndrome. Eur. J. Hum. Genet. 14: 39-48. PubMed ID: 16251895

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

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ORDER OPTIONS

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2) Select Additional Test Options

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Note: acceptable specimen types are whole blood and DNA from whole blood only.
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