We report four sibs with Kenny-Caffey syndrome in a consanguineous Bedouin family. The first two died in the neonatal period while the remaining affected brother and sister had all the characteristic clinical, biochemical, and radiological abnormalities of the syndrome. These included severe pre- and postnatal growth retardation, cortical thickening of the tubular bones with medullary stenosis, eye abnormalities, facial dysmorphism, hypocalcaemia, and low levels of parathyroid hormone. The children also showed intracranial calcification, impaired neutrophil phagocytosis, increased proportion of B lymphocytes, reduced CD4 and CD8 subpopulations of T lymphocytes, and inhibited transformation in response to Candida antigen. Fluorescence in situ hybridisation (FISH) was applied to blood lymphocyte metaphase spreads from these two Bedouin sibs and their parents using probe D22S75 (Oncor), specific for the DiGeorge critical region on chromosome 22q11.2. The presence of 22q11.2 haploinsufficiency was identified in the affected sibs, which was transmitted from the phenotypically normal mother. The present report widens the spectrum of CATCH 22 microdeletion to accommodate Kenny-Caffey syndrome.