1.2. Shank family
The Shank family consists of postsynaptic scaffolding proteins central to the formation and function of protein complexes at the postsynaptic density (PSD) \cite{RN31,RN5}. There are three SHANK isoforms (SHANK1, SHANK2, SHANK3), all of which have been linked to ASD \cite{RN31,RN5}, with a deficiency in SHANK3, a gene that maps to the chromosomal region critical to 22q13.3 deletion syndrome, found in close to 1% of ASD cases \cite{RN33,RN32}. However, all three genes are subject to alternative splicing and express a number of protein isoforms with unique interaction domains, complicating a simple mechanistic model of their role in the disorder. Mouse models of specific mutations or loss-of-function of specific protein isoforms have been useful in untangling their roles at the synaptic and circuit level \cite{RN34}.