SPG4 and the heart: coincidence or clue? What two cardiologists say

A plain-language summary of a published scientific study. It is educational and does not replace medical advice.

The study: Panjrath G, Dakhakhni M, JACC: Case Reports, 12 August 2026[1]. An editorial comment (the authors' opinion). Free full text.

What the commentary is about

The same journal described the first known case of a person with SPG4 who also developed dilated cardiomyopathy, a condition in which the heart enlarges and pumps more weakly[2]. Two cardiologists discuss whether the two are linked or simply occurred together[1].

The arguments they make

• A precedent. Friedreich ataxia was considered a purely neurological disease until it was found to affect the heart too; guidelines now require heart check-ups for these patients[1].
• Little data in HSP. An earlier report described two people with hereditary spastic paraplegia and cardiomyopathy of unknown cause, but no larger studies followed[1].
• Clues from the lab. In animals, switching off the SPAST gene increased the risk of stress-induced arrhythmias without changing the heart's structure or function. Transport of connexin 43, a protein that helps electrical signals pass between heart cells, was also affected[1].
• It is not known whether people with SPAST variants are more vulnerable to such problems[1].

What it means for families

• There are no official recommendations yet for heart check-ups in SPG4[1].
• The authors suggest that neurologists also ask about heart symptoms and consider an electrocardiogram (ECG), a cheap and widely available test[1].
• If symptoms such as breathlessness on exertion appear, the authors recommend a timely cardiology consultation[1,2].

What the study does not tell us yet

This is an opinion piece, not a study. A single case cannot prove a causal link, and heart involvement in SPG4 has not been established[1]. Nor do the authors recommend SPAST testing for people with dilated cardiomyopathy[1].