Type I SMA: the absence of speech is accompanied neither by an inability to decipher verbal language, nor by cognitive impairment

An Italian study carried out in 22 children with type I SMA, aged 3 to 11 years, without clear and understandable speech but able to communicate at least by yes and no, showed: 

  • a median IQ of 120 on the Raven Progressive Matrix Multiple Choice Intelligence Test;
  • a normal level of morphosyntactic comprehension on a children’s grammar comprehension test;
  • an average speech score of 5 on a scale of 1 (non-vocal) to 10 (normal speech process), lower in the most affected children.

Thus, despite a very severe motor and speech impairment, children with type I SMA without disease-modifying treatment present an overall cognitive level lying in a range slightly higher than that of the general population with a level of language comprehension. normal verbal.


Intellectual abilities, language comprehension, speech, and motor function in children with spinal muscular atrophy type 1. Grazia Zappa, Antonella LoMauro, Giovanni Baranello, Emilia Cavallo, Priscilla Corti, Chiara Mastella, Maria Antonella Costantino. J Neurodev Disord. 2021 Feb 2;13(1):9.