Diseases Studied

The Rare Diseases Clinical Research Network is an NIH-funded research network of 20 active consortia or research groups working to advance treatment for diseases that are rare. Use the search tools on this page to find the diseases we currently study. You can reach out to the indicated consortia or research groups for more information on those diseases and studies underway.

This network focuses on clinical research and does not generally support clinical care outside of research activities. To learn about other rare diseases, please visit the Genetic and Rare Diseases Information Center (GARD), which is an NIH program that helps the public find reliable information about rare and genetic diseases. Their staff are specialists. Contact them at 1-888-205-2311 or email GARDinfo@nih.gov.

All Diseases > Primary Lateral Sclerosis

Primary Lateral Sclerosis (PLS)

Disease Category: ALS and Related Disorders

A rare disorder affecting the central motor neurons (nerves of the brain and spinal cord) which send messages to control voluntary muscles. The hallmark characteristic is progressive, but painless, muscle weakness and spasticity (muscle stiffness), usually beginning in the legs. The disease progresses at varying rates, eventually affecting the hands and base of the brain, resulting in dysphagia (difficulty swallowing) and dysarthria (difficulty speaking).

Research groups studying this disease

ALS and Related Disorders
CReATe logo

Clinical Research in ALS and Related Disorders for Therapeutic Development (CReATe)

CReATe logo


The PGB2 (Phenotype-Genotype and Biomarker) Study of the CReATe Consortium will prospectively and systematically study approximately 300 patients with amyotrophic lateral sclerosis (ALS) or a related neurodegenerative disorder such as ALS-frontotemporal dementia (FTD), primary lateral sclerosis (PLS), hereditary spastic paraplegia (HSP), progressive muscular atrophy (PMA), and multisystem proteinopathy (MSP). The study is broadly inclusive, enrolling patients with both familial and sporadic forms of disease. All enrolled patients will undergo five in-person evaluations at one of the CReATe consortium clinical sites as well as annual remote evaluations. In-person evaluations will include motor, cognitive and functional assessments as well as collection of biological fluids. Remote evaluations will focus on functional status and disease staging. Family members of patients with apparently sporadic disease (i.e. no family history) may also participate through a remote-evaluation process in which they provide limited information about their medical history as well as biological samples (blood and urine). Every effort will be made to integrate study procedures into multi-disciplinary clinic visits to minimize the burden of participation on patients and their families.

Supports research to cure two similar upper motor neurological diseases: hereditary spastic paraplegia and primary lateral sclerosis.