Here, we present the first report of a female patient with RTT-like phenotype caused by SHANK3 (SH3 and multiple ankylin repeat domain 3) mutation, indicating that the clinical spectrum of SHANK3 mutations may extend to RTT-like phenotype in addition to (severe) developmental delay, absence of expressive speech, autistic behaviors and intellectual disability.
Haploinsufficiency of the SHANK3 gene causes a developmental disorder, 22q13.3 deletion syndrome (known as Phelan-McDermid syndrome), that is characterized by severe expressive language and speech delay, hypotonia, global developmental delay, and autistic behavior.