DNA icon

Welander Distal Myopathy via the TIA1 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
TIA1 81479 81479,81479 $990
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
11745TIA181479 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.

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.


Genetic Counselors


  • Angela Gruber, PhD

Clinical Features and Genetics

Clinical Features

Welander distal myopathy (OMIM 604454) is an adult onset disorder characterized by weakness and wasting of hand muscles with slow progression to involve the leg muscles. The presenting clinical sign is usually fine motor clumsiness involving the index finger and thumb (Ahlberg et al. 1999). Atrophy of the hand muscles occurs over time. Gait difficulties including stumbling and falls develop because of anterior tibial muscle weakness and subsequent inability to raise the foot normally. Muscle biopsies from patients show variable fiber diameter, atrophic fibers, and rimmed vacuoles (Klar et al. 2013). Immunostaining of atrophic muscle reveals TIA1-positive cytoplasmic aggregates or granules (Hackman et al. 2013).


Welander distal myopathy is typically an autosomal dominant disorder limited to individuals of Nordic heritage (Hackman et al. 2013). All Welander distal myopathy patients reported to date have the same missense variant (p.Glu384Lys) in the TIA1 gene (OMIM 603518). Because the p.Glu384Lys variant is relatively common in Finland and Sweden, at least one homozygous patient has been reported (Ahlberg et al. 1999). The patient was affected earlier in life and proximal muscle involvement was present. TIA1 encodes a stress-induced, RNA-binding protein which participates in regulation of gene expression through splicing regulation and translational repression.

The TIA1cytotoxic granule-associated RNA-binding protein' is coded by exons 1-13 of the TIA1 gene located on chromosome 2p13.3.

Clinical Sensitivity - Sequencing with CNV PGxome

To date, the only known cause of Welader distal myopathy is the p.Glu384Lys mutation in exon 13 of the TIA1 gene. Clinical and analytical sensitivity should be high for symptomatic individuals of Nordic heritage.

Testing Strategy

This test provides full coverage of all coding exons of the TIA1 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

Adult onset distal myopathy in patients of Finnish or Swedish background. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in TIA1.


Official Gene Symbol OMIM ID
TIA1 603518
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT


Name Inheritance OMIM ID
Welander distal myopathy AR, AD 604454


  • Ahlberg G, Tell D von, Borg K, Edström L, Anvret M. 1999. Genetic linkage of Welander distal myopathy to chromosome 2p13. Ann. Neurol. 46: 399–404. PubMed ID: 10482271
  • Hackman P, Sarparanta J, Lehtinen S, Vihola A, Evilä A, Jonson PH, Luque H, Kere J, Screen M, Chinnery PF, Ahlberg G, Edström L, et al. 2012. Welander distal myopathy is caused by a mutation in the RNA-binding protein TIA1. Ann. Neurol. PubMed ID: 23401021
  • Klar J, Sobol M, Melberg A, Mäbert K, Ameur A, Johansson ACV, Feuk L, Entesarian M, Orlén H, Casar-Borota O, Dahl N. 2013. Welander distal myopathy caused by an ancient founder mutation in TIA1 associated with perturbed splicing. Hum. Mutat. 34: 572–577. PubMed ID: 23348830


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

loading Loading... ×


An error has occurred while calculating the price. Please try again or contact us for assistance.

View Ordering Instructions

1) Select Test Method (Platform)

1) Select Test Type

2) Select Additional Test Options

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
Total Price: loading
Patient Prompt Pay Price: loading
A patient prompt pay discount is available if payment is made by the patient and received prior to the time of reporting.
Show Patient Prompt Pay Price
Copy Text to Clipboard