These include the TRF1-interacting, ankyrin related ADP-ribose polymerase gene (TNKS, OMIM*603303) for behavioural difficulties, and the SRY-Box 7 transcription factor (SOX7, OMIM *612202) for the developmental delay, as mutations of the related SOX3 gene have been associated with X-linked mental retardation [28]. The gene discussed is TNKS; the disease is Global developmental delay.