What BetterLife Data Tell Us About Genetic Testing in FSHD

By: Feng Kok, Kayleigh Worek 

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For most people living with Facioscapulohumeral Muscular Dystrophy (FSHD), a genetic test is more than a lab result. It’s confirmation after years of unanswered questions, clarity for family members trying to understand their own risk, and, increasingly, the gateway to clinical trials and treatments that require a documented diagnosis. Yet for many in our community, that confirmation is slow to arrive or may never arrive at all.  

In this piece, we bring together two sources of evidence to look at that burden. First, we review what recent peer-reviewed research tells us about diagnostic delay, and misdiagnosis. Then we turn to BetterLife FSHD to see how those patterns show up in the survey responses of 508 people who shared their genetic testing journeys with us. Together, they point to the same conclusion: closing the diagnostic gap can help families make informed decisions and prepare our community for possible treatments on the horizon. 

The Hidden Cost of Diagnostic Delay 

Getting a clear diagnosis for FSHD should be straightforward, but recent research confirms what patients have experienced for decades: the pathway to confirmation is often long and fraught with uncertainty. 

A landmark 2026 study by Ji et al. evaluated patient-reported outcomes to understand the multidimensional burden of FSHD. Their findings revealed a stark reality: 

• A 9.8-Year Diagnostic Delay: On average, patients wait nearly a decade from the onset of their initial symptoms to receive a definitive genetic confirmation.

• High Misdiagnosis Rates: 57% of participants reported being misdiagnosed at least once along their journey.

Understanding the Types of Genetic Testing for FSHD 

Why does getting a diagnosis take so long? Unlike many conditions that can be identified with a basic blood panel, FSHD requires specialized genetic analysis because of its complex structure on Chromosome 4. Knowing which test is being performed can help you navigate conversations with your care team: 

• Optical Genome Mapping (OGM): A modern, highly accurate testing technology that analyzes long intact strands of DNA. It quickly identifies the size of D4Z4 repeat contractions on Chromosome 4 (the hallmark of FSHD1) without the delays of older methods.

• Next-Generation Sequencing (NGS) & Exome Sequencing: Primarily used to identify variants in the SMCHD1 gene (associated with FSHD2) or to rule out other neuromuscular conditions.

• Southern Blot Analysis: Historically considered the traditional “gold standard” for FSHD1, this labor-intensive method estimates the size of DNA fragments. While effective, it is increasingly being replaced or supplemented by newer technologies like OGM to speed up results.

Tests can sometimes return inconclusive results, extending the diagnostic delay even further and compounding family stress. 

The Ripple Effect on Families 

Uncertainty doesn’t stop with the individual. A systematic review by Srinivasan et al. (2020) looked at cascade testing, the process of testing biological relatives once one family member has a genetic diagnosis. The article found that whether someone discloses their genetic risk to relatives is shaped by a mix of individual, family, and systemic factors: gaps in understanding who else might be at risk, concerns about how relatives will react, limited or strained family contact, and practical barriers like insurance coverage and access to genetic services. 

What BetterLife Survey Data Tells Us 

Note: The following data represents self-reported survey responses from BetterLife FSHD participants located in the United States. 

We surveyed 508 people in the BetterLife FSHD Registry about their genetic testing journey, and the patterns in their answers echo the research above in ways.  

Most Respondents Have Been Tested, But Our Sample Isn’t the Full Picture 

Eighty-six percent of respondents in the BetterLife FSHD Registry (437/508) told us they have been genetically tested for FSHD. Before drawing broader conclusions from that number, it’s worth naming an important limitation: BetterLife is not a random sample of everyone living with FSHD. People who join a patient registry, complete a detailed survey, and engage with an advocacy organization are, by definition, already more connected to the FSHD community and its resources than the general FSHD population. It’s likely that this 86% figure overstates how many people with FSHD nationwide have actually been genetically confirmed and that the barriers described below are even more common, and more consequential, outside of an engaged registry population like ours. 

With that caveat in mind, the responses from the 38 people in our sample who have not been tested are still instructive. Of those 38, 34 shared their reasons why: 

• The most common reason was a sense that testing wasn’t necessary: 53% (18/34) said, “I already know FSHD is in my family.”

• Financial and systemic barriers were close behind: almost one-third (29%, 10/34) said they “can’t afford genetic testing,” and 21% (7/34) said they don’t have insurance or their insurance doesn’t cover it.

• About a third of respondents (13/38, 34%) cited more than one overlapping reason—for example, people who mentioned cost were also likely to mention lacking insurance coverage, suggesting these barriers tend to stack rather than occur in isolation.

• For a smaller group (3/38, 8%), the barrier was emotional: fear, denial, or uncertainty about whether testing was worth pursuing.