Intelligence is normal, but the lifespan is greatly shortened; affected persons seldom survive beyond age 20.
[britannica.com]
[…] usually normal.
[glosbe.com]
[…] the clinical features include short stature, hepatosplenomegaly, dysostosis multiplex, stiff joints, corneal clouding, cardiac abnormalities, and facial dysmorphism, with intelligence
[glosbe.com]