ALS Testing Expected to Drive Sharp Rise in Clinic Visits

Genetic testing of people with a family member diagnosed with amyotrophic lateral sclerosis (ALS) will greatly increase the number of clinic visits to specialized ALS centers over the next decade, a population model showed.

Based on estimates of four common gene variants — SOD1, C9orf72, FUS, and TARDBP — 2,704 people in the U.S. had a symptomatic gene-related form of ALS in 2026 and 10,944 people were asymptomatic gene carriers, reported Jennifer Morganroth, MD, of Massachusetts General Hospital in Boston, and co-authors.

By 2035, those numbers are expected to rise to 7,474 symptomatic ALS patients and 26,111 asymptomatic gene carriers, the researchers wrote in Neurology Genetics.

Fewer than 50 extra clinic visits were needed annually per ALS center in most states in 2026, with 12 states needing 50 to 99 additional clinic visits and no states surpassing 100. By 2035, only six states would remain below 50 visits per ALS center annually; 22 states would have 50 to 99 visits, 18 states would have 100 to 199, and three would exceed 200.

“As more at-risk relatives get genetic testing, the testing will identify more gene carriers, so specialized ALS centers must plan for the long-term care of more people,” Morganroth said in a statement.

“Anticipating the clinical needs of people with a genetic risk for ALS, and which states may see the greatest increases in this patient population, is essential for improving care and ensuring that clinics are ready as new therapies become available,” she continued. “This will become increasingly important as gene-targeted therapies, biomarker monitoring, and preventive trials continue to emerge.”

The first gene-targeted ALS treatment — tofersen (Qalsody), an antisense oligonucleotide that targets mRNA to reduce SOD1 protein synthesis — was approved in 2023 and has slowed decline in some patients with SOD1-ALS. Other drugs, like investigational jacifusen for FUS-ALS, are being studied. Consensus guidelines recommend that genetic testing should be offered to all people with ALS, regardless of their family history.

ALS clinics already contend with growing numbers of patients with symptomatic ALS amid deep funding cuts, Morganroth and co-authors noted.

“While current ALS center capacity may meet present needs, many clinics are already operating at or near full capacity caring for symptomatic patients, and recent funding cuts to the Muscular Dystrophy Association and ALS Association further threaten sustainability,” they wrote.

“These financial and operational pressures underscore the fragility of the current system and how even modest increases in patient volume could challenge care delivery,” they added.

In their analysis, the researchers used two complementary methods to estimate ALS prevalence by state. In one approach, they applied race-specific ALS prevalence and incidence rates from a population-based study in the metropolitan Atlanta region to 2023 census demographic data. In the other, they used state-level ALS prevalence and incidence estimates derived from the 2011-2018 National ALS Registry, which identified cases in Medicare, Veterans Health Administration, and Veterans Benefits Administration records.

Morganroth and colleagues calculated the number of gene-positive cases using published frequencies of pathogenic variants, assuming 7% of ALS cases were attributable to C9orf72 mutations, 2% to SOD1, 0.5% to FUS, and 0.4% to TARDBP. They estimated an average of 4.25 carrier relatives per proband and one annual ALS center visit for each asymptomatic carrier.

The researchers acknowledged that their projections, anchored to a modeled first year of 2026, are not precise forecasts. They also noted that ALS center counts were based on the I AM ALS directory, which may not include unaffiliated neuromuscular centers.

The study excluded de novo variants, assumed in-state care, and did not account for family mobility across states, Morganroth and colleagues pointed out.

“Future work should integrate laboratory and registry data, demographic-specific penetrance, family mobility, and observed testing behavior, and evaluate the feasibility and effectiveness of dedicated carrier clinics and telehealth-based surveillance,” they wrote.

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