Moreover, similar missense variants in FAM111A have also been identified in patients with osteocraniostenosis (OCS) — also termed gracile bone dysplasia (GCLEB; OMIM 602361), a severe skeletal condition that is often fatal (16, 20) — and in a patient with severe growth impairment thought to have primary deficiency of insulin-like growth factor 1 (22). This evidence concerns the gene IGF1 and osteocraniostenosis.