Homozygous loss of function mutations in KCNJ1 cause the autosomal recessive condition antenatal Bartter syndrome, type 2. Tyson et al, 2008, PMID: 19000322 report two patients with intellectual disability who have large deletions that include KCNJ1. One patient also has a large duplication of 11q24.2q25 material. All imbalances were de novo. The deletions included many other genes. The authors compare phenotypes to Jacobsen syndrome.