Spastic Paralysis, Infantile-Onset Ascending, also known as iahsp, is related to spastic paraplegia 20, autosomal recessive and spastic paraparesis, and has symptoms including muscle weakness and facial paresis. An important gene associated with Spastic Paralysis, Infantile-Onset Ascending is ALS2 (Alsin Rho Guanine Nucleotide Exchange Factor ALS2). Affiliated tissues include spinal cord and eye, and related phenotypes are spasticity and hyperreflexia