Firstly, two cases of de novo proximal 16p 11.2 deletion CNVs involving the recurrent BP4 and BP5 breakpoint (BP) regions, including the morbid gene TBX6 (MIM: 611913), were detected in this study; the deletion of this region may be associated with developmental delay, cognitive impairment, language delay, autism spectrum disorder, delayed language development, or minor dysmorphic facial features. The gene discussed is TBX6; the disease is Cognitive impairment.