Lithium as a rescue therapy for regression and catatonia features in two SHANK3 patients with autism spectrum disorder: case reports.

Phelan-Mc Dermid syndrome is a contiguous disorder resulting from 22q13.3 deletion implicating the SHANK3 gene. The typical phenotype includes neonatal hypotonia, moderate to severe intellectual disability, absent or delayed speech, minor dysmorphic features and autism or autistic-like behaviour. Recently, point mutations or micro-deletions of the SHANK3 gene have been identified, accompanied by a phenotype different from the initial clinically description in Phelan McDermid syndrome.