About FSHD

Facioscapulohumeral Muscular Dystrophy (FSHD) is one of the most common forms of muscular dystrophy, affecting approximately 1/8,000 individuals worldwide. As the name implies, this condition primarily affects the muscles of the face, shoulder blades, and upper arms as well as the lower legs and causes a progressive wasting of these muscles. Symptoms of this condition usually appear in adolescence; however, the age of onset and severity can vary from a severe infantile form to a less-severe late adulthood condition.

FSHD is categorized into two types based on the underlying genetic cause. FSHD type 1 (FSHD1) is the more common type of FSHD, accounting for up to 95% of cases. An autosomal dominant condition, FSHD1 is caused by a contraction of a repeat unit known as D4Z4 located on chromosome 4. FSHD type 2 (FSHD2) is associated with digenic inheritance and is caused by variants in the SMCHD1 gene.

Summary of Testing Options

  • FSHD Type 1 Assay utilizing whole genome optical mapping technology that includes:

    • An accurate repeat count of the D4Z4 region at 4q35, with the ability to detect disease-causing contractions defined as fewer than 10 repeats
    • An accurate repeat count of the D4Z4 region at 10q26, which is not associated with disease but is nearly identical to the 4q35 region
    • Haplotyping of the 4q allele
  • FSHD Type 2 Assay utilizing next-generation sequencing that includes:
    • Sequencing and deletion/duplication analysis of the SMCHD1 gene
    • Complete coverage of all exons of the SMCHD1 gene, with greater than 150x average coverage
  • Additional Assays
    • Comprehensive Neuromuscular Panel that includes sequencing and deletion/duplication analysis for 133 genes that have been associated with neuromuscular disease

Benefits of Testing with Us

  • Utilization of Whole Genome Optical Mapping technology for FSHD Type 1 Testing, which allows for a more accurate count of the D4Z4 repeat array at both 4q35 and 10q26 compared to traditional technologies.
  • Enhanced flexibility in ordering FSHD and other neuromuscular genetic testing.
    • Ability to test for FSHD type 1 and type 2.
    • Ability to order a more comprehensive neuromuscular genetic testing panel.
  • Ability to consolidate comprehensive FSHD and neuromuscular related testing to a single laboratory.
  • Increased Accessibility to Testing: PerkinElmer Genomics’ position as an industry leader in Next-Generation Sequencing (NGS) and genomic testing solutions allows us to introduce unmatched automation and efficiencies in our clinical laboratory. These cost savings are passed on to our patients via industry-leading pricing.
Order Testing

FSHD Testing Options

Test Code Test Name Turn Around Time
D8000 FSHD Type 1 Testing (D4Z4 repeat size)

3-5 weeks Order Test
D5132 FSHD Type 2 Test

1 Gene

3-5 weeks Order Test

How to Order

1. Complete and print the FSHD test requisition.

Ensure that:

  •      All sections are complete
  •      You have the correct test code
  •      Your patient has signed an informed consent

2. Collect patient sample.

Obtain a sample for testing from the patient and confirm that the sample is correctly labeled with the patient’s name and date of birth.

Note: if you do not have a PerkinElmer Genomics FSHD collection kit available in your office, please email or call us at 1-866-354-2910.

3. Send patient sample.

Ship your test kit back using the pre-paid shipping label. Remember to include:

✔   Patient sample

✔   Coolant pack for temperature regulation

✔   Completed informed consent

✔   Test requisition form

✔   Any applicable medical records or clinical notes

IMPORTANT: All samples for FSHD1 testing must be sent to PerkinElmer Genomics the same day it is drawn for optimal sample quality.


Requisition Form – FSHD Testing


  • Refrigerated whole blood is required for any assay that includes the FSHD type 1 assay. Refrigerated whole blood is required due to the proprietary extraction method utilized for the assay.
  • Other sample types may be acceptable for the standalone FSHD2 and/or neuromuscular panel tests. Please contact the laboratory for more details.

The FSHD type 1 test utilizes Whole Genome Optical Mapping to accurately detect the D4Z4 contraction (fewer than 10 repeats) known to cause FSHD type 1. For more information about the technology, please view our test information sheet.

This test includes full sequencing and deletion/duplication analysis of the SMCHD1 gene utilizing next-generation sequencing.

This test includes full sequencing and deletion/duplication analysis of the 133 genes on the comprehensive neuromuscular panel utilizing next-generation sequencing.

Haplotyping of the 4q allele is included for any tests where whole genome optical mapping is utilized to determine the repeat count at 4q35 and 10q26. Haplotyping is not included with tests where only sequencing is performed.

Methylation studies of the 4q alleles are not included at this time.

If you have additional questions, please feel free to email or call us at 1-866-354-2910.