SOX5 and developmental and speech delay due to SOX5 deficiency: Heterozygous 12p12 deletions and a reciprocal t(11;12) translocation disrupting either SOX5 alone or SOX5 together with other genes have been reported in patients presenting with ID, global developmental delay, language and motor impairment, and mild dysmorphic facial features [35], which collectively characterize the neurodevelopmental disorder Lamb-Shaffer syndrome (OMIM-616803).