Science's fight against hereditary muscle stiffness

Advances in neurogenetics over the past two decades have transformed the understanding of Hereditary Spastic Paraparesis (HSPs), a group of rare diseases that cause degeneration of motor neurons, resulting in stiffness and weakness in the lower limbs. If in 2008 only 17 subtypes were known, today science has identified almost a hundred. "Currently, more than 90 different subtypes of these diseases have been described, each caused by changes in a specific gene in human DNA", explains Dr. Jonas Alex Morales Saute, professor at UFRGS and researcher at Hospital de Clínicas de Porto Alegre (HCPA). According to the expert, the leap occurred thanks to new generation sequencing (Exome), which reduced costs and expanded access to diagnosis.

SUBDIAGNOSIS - In Brazil, underdiagnosis is still a challenge, often confused with cerebral palsy in children. However, the iAXON-Brazil network, coordinated by Saute, seeks to change this scenario. With seven centers in the country, the network has already evaluated 160 patients and plans to reach 300 by 2027. The focus is to create a repository of biomarkers and test digital sensors to measure gait.

The ultimate goal is to take a leading role in modifying therapies. "We are experiencing a therapeutic revolution for genetic diseases. The current challenge is to define how to adequately measure the effectiveness of these new therapies", says Saute. In Rio Grande do Sul, the high frequency of the SPG76 subtype led the group to begin research into a national gene therapy.

PHYSIOTHERAPY - While the cure is sought in laboratories with animal models and cell lines, the health system needs to respond to the daily lives of patients. "Symptomatic treatments, especially motor physiotherapy, need to be maintained continuously", warns the doctor, reinforcing that diagnosis is the first step towards visibility and quality of life.