GTF2I and Cognitive impairment: We demonstrate that patients whose deletion includes all 3 GTF2I family members have additional cognitive impairments involving spatial, social and executive functioning, which may be a consequence of haploinsufficiency for GTF2IRD2. Two atypical patients with smaller deletions, but including GTF2IRD2, also showed this distinctive neuropsychological profile, providing further evidence of the importance of this gene in this phenotype.