Lamb-Shaffer syndrome (LAMSHF, OMIM: 616803) is a neurodevelopmental disorder caused by chromosome 12 deletions ranging from a few kilobases to several trillion bases, including at least a part of the SOX5 gene, in addition, frame shift variants, splicing variants, nonsense variants and missense variants also cause the disease, which is autosomal dominantly inherited [1]. The gene discussed is SOX5; the disease is 12p12.1 microdeletion syndrome.