1% in public databases (such as the 1,000 Genomes Project, Genome Aggregation Database, Exome Sequencing Project and ExAC) and our internal database, we used the TGex software (LifeMap Sciences, USA) to map 11 candidate variations in 10 genes (MBD5, LAMA1, CDON, PLXNA1, ASH1l, GABBR2, TBR1, CHAMP1, JAG2 and WDR26) to the known phenotypes (including global developmental delay, delayed speech and language development, autistic behaviour, behavioural abnormalities, hypotonia, seizures and intellectual disability), and then extracted the variations (Supplementary Table S1). Here, CDON is linked to Intellectual disability.