Gracile bone dysplasia (GCLEB; MIM 602361) and Kenny-Caffey syndrome, type 2 (KCS2; MIM 127000) are autosomal dominant disorders caused by mutations in the FAM111A gene. They share clinical features such as short stature, thin long bones, primary hypoparathyroidism, hypocalcemia, microphthalmia, triangular face and frontal bossing. Radiographs show increased bone density with small and slender bones. GCLEB is more severe and it is usually perinatally lethal. The additional features of GCLEB include premature closure of basal sutures,  cloverleaf skull deformity due to underossified bone with resultant soft tissue protrusion, deficient calvarial mineralization, flared metaphyses and fractures. Patients with KCS2 are small at birth, have delayed closure of the anterior fontanelle and hyperopia. Episodic hypocalcemic tetany and convulsions are common.  Kenny-Caffey syndrome, type 1 (KCS1; MIM 244460) is  the autosomal recessive form of KCS. It is caused by mutations in the TBCE gene. The clinical phenotype of KCS1 is similar to KCS2, but the psychomotor development of KCS1 patients is delayed.