For families living with Hereditary Spastic Paraplegia (HSP) and Primary Lateral Sclerosis (PLS), the urgent need for therapies is no less real than it is for ALS. These progressive neurodegenerative diseases share critical biological, cellular, and clinical pathways with ALS—including motor neuron vulnerability, axonal degeneration, mitochondrial dysfunction, protein trafficking defects, and neuroinflammation—making them scientifically relevant to the broader fight against neurodegeneration. Investing in HSP and PLS is not separate from advancing ALS research; it strengthens it. Studying these rare disorders can unlock earlier mechanistic insights, reveal therapeutic targets, and accelerate discoveries that may benefit multiple neurodegenerative diseases, including ALS. Through the Spastic Paraplegia Foundation (SPF), patients, families, and advocates urge Congress to fulfill the broader promise of the Act for ALS by ensuring its implementation includes HSP, PLS, and other rare neurodegenerative diseases Congress intended to support—because breakthroughs in one disease can drive progress for many.
The Act for ALS (Public Law 11779), signed into law in December 2021, represents a landmark, bipartisan commitment to accelerating research and therapeutic development for rare neurodegenerative diseases. The rare disease community deeply values Congress’s leadership in recognizing the urgent unmet need facing individuals and families affected by these devastating conditions.
Importantly, Congressional intent behind the Act was not limited to ALS alone. Several provisions of the law were explicitly designed to support rare neurodegenerative diseases beyond ALS, acknowledging shared scientific, regulatory, and clinical challenges across multiple conditions, including hereditary spastic paraplegia (HSP) and primary lateral sclerosis (PLS).
However, according to a recent Government Accountability Office report (GAO-26-107691), implementation of the Act to date has focused exclusively on ALS research. As a result, the promise of the Act for individuals living with other rare neurodegenerative diseases has not yet been realized.
As members of the rare neurodegenerative disease community, we respectfully urge Congress to ensure that implementation of the Act for ALS aligns fully with its original intent. Specifically, we ask Congress to:
Provide a dedicated appropriation to the U.S. Food and Drug Administration to support full implementation of Sections 3 and 5 of the Act, enabling FDA led activities that advance regulatory readiness and therapeutic development for rare neurodegenerative diseases beyond ALS.
Direct the National Institutes of Health to utilize Act for ALS funding to support research on rare neurodegenerative diseases beyond ALS, consistent with the language and purpose of the statute.
There are hundreds of rare neurological conditions for which no disease modifying treatments exist. Patients and families affected by HSP, PLS, and related disorders face long diagnostic journeys, few therapeutic options, and limited research investment. They have been waiting far too long.
We urge Congress to help ensure that the full potential of the Act for ALS is realized and that its benefits extend to all rare neurodegenerative disease communities Congress intended it to serve.

Act for ALS and Rare Neurodegenerative Diseases Beyond ALS Act for ALS

For families living with Hereditary Spastic Paraplegia (HSP) and Primary Lateral Sclerosis (PLS), the urgent need for therapies is no less real than it is for ALS. These progressive neurodegenerative diseases share critical biological, cellular, and clinical pathways with ALS—including motor neuron vulnerability, axonal degeneration, mitochondrial dysfunction, protein trafficking defects, and neuroinflammation—making them scientifically relevant to the broader fight against neurodegeneration. Investing in HSP and PLS is not separate from advancing ALS research; it strengthens it. Studying these rare disorders can unlock earlier mechanistic insights, reveal therapeutic targets, and accelerate discoveries that may benefit multiple neurodegenerative diseases, including ALS. Through the Spastic Paraplegia Foundation (SPF), patients, families, and advocates urge Congress to fulfill the broader promise of the Act for ALS by ensuring its implementation includes HSP, PLS, and other rare neurodegenerative diseases Congress intended to support—because breakthroughs in one disease can drive progress for many.

The Act for ALS (Public Law 11779), signed into law in December 2021, represents a landmark, bipartisan commitment to accelerating research and therapeutic development for rare neurodegenerative diseases. The rare disease community deeply values Congress’s leadership in recognizing the urgent unmet need facing individuals and families affected by these devastating conditions. Importantly, Congressional intent behind the Act was not limited to ALS alone. Several provisions of the law were explicitly designed to support rare neurodegenerative diseases beyond ALS, acknowledging shared scientific, regulatory, and clinical challenges across multiple conditions, including hereditary spastic paraplegia (HSP) and primary lateral sclerosis (PLS).

However, according to a recent Government Accountability Office report (GAO-26-107691), implementation of the Act to date has focused exclusively on ALS research. As a result, the promise of the Act for individuals living with other rare neurodegenerative diseases has not yet been realized.

As members of the rare neurodegenerative disease community, we respectfully urge Congress to ensure that implementation of the Act for ALS aligns fully with its original intent. Specifically, we ask Congress to:

--Provide a dedicated appropriation to the U.S. Food and Drug Administration to support full implementation of Sections 3 and 5 of the Act, enabling FDA led activities that advance regulatory readiness and therapeutic development for rare neurodegenerative diseases beyond ALS.

--Direct the National Institutes of Health to utilize Act for ALS funding to support research on rare neurodegenerative diseases beyond ALS, consistent with the language and purpose of the statute.

There are hundreds of rare neurological conditions for which no disease modifying treatments exist. Patients and families affected by HSP, PLS, and related disorders face long diagnostic journeys, few therapeutic options, and limited research investment. They have been waiting far too long.

We urge Congress to help ensure that the full potential of the Act for ALS is realized and that its benefits extend to all rare neurodegenerative disease communities Congress intended it to serve.