Kenny-Caffey syndrome is an extremely rare hereditary skeletal disorder characterized by thickening of the long bones, thin marrow cavities in the bones (medullary stenosis), and abnormalities affecting the head and eyes. Most cases are obvious at birth (congenital). The primary outcome of Kenny-Caffey syndrome is short stature. Mental abilities are rarely affected. Individuals with Kenny-Caffey syndrome may also have recurrent episodes of low levels of calcium in the blood stream (hypocalcemia) that is caused by insufficient production of parathyroid hormones (hpoparathyroidism). In most cases, Kenny-Caffey syndrome is inherited as an autosomal dominant trait. Other cases are inherited as an autosomal recessive trait. X-linked autosomal recessive inheritance has not been ruled out.