Childhood-onset HSP: what a study of 91 children in Spain shows

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

The study: Espasandin-Hueter N et al., European Journal of Paediatric Neurology, published online 29 October 2026[1]. A retrospective study across several centres in Spain. Only the abstract is freely available.

What the researchers studied

Hereditary spastic paraplegia (HSP) is a group of genetic conditions in which the legs gradually become stiff and weak; SPG4 is one of them. The team collected the records of children diagnosed with HSP between 2004 and 2024 at several Spanish referral hospitals, after other causes of leg stiffness had been ruled out[1]. They looked at symptoms, imaging, neurological tests and genetic results.

What they found

• 91 children from 87 families were included[1].
• First signs appeared at a median age of 12 months. The most common were global developmental delay and walking difficulties[1].
• 45% had a "pure" form (mainly affecting the legs) and 55% a "complex" form, most often with speech difficulties and intellectual disability[1].
• 69% were isolated cases, with no other known relative affected[1].
• MRI showed changes in 61% of children, mostly a thin corpus callosum and areas of altered white matter[1].
• A genetic cause was found in 62%, mostly through exome sequencing (WES). SPAST (the SPG4 gene), CTNNB1 and KIF1A were the genes involved most often[1].

What it means for families

• A child can have HSP even when nobody else in the family does: most cases in the study were isolated[1].
• Broad genetic testing found the cause in almost two thirds of children. The lowest yield was in children with a pure form and no family history[1].
• 58% of the variants were in genes not regarded as "classic" HSP genes[1], so a test limited to a few genes can miss the cause.

What the study does not tell us yet

The study covers children with many types of HSP, not only SPG4, and relies on existing medical records. The authors stress that rating scales designed for children are still missing and are needed to follow the course of the disease properly[1]. The results are group averages, not a prediction for any one child: a paediatric neurologist and a clinical geneticist can explain what they mean for your family.