Variants in the SEC24D gene cause Cole-Carpenter syndrome type 2 or osteogenesis imperfecta. Cole-Carpenter syndrome type 2 is characterized by bone fragility with craniosynostosis (a baby's skull joins together too early), ocular proptosis (the protrusion of the eye), hydrocephalus (the accumulation of cerebrospinal fluid within the brain), and distinctive facial features. Patients are diagnosed with osteogenesis imperfecta when syndromic or dysmorphic features are not observed. Six families reported thus far, 3 families were diagnosed with Cole-Carpenter syndrome type 2 and the other 3 families were diagnosed with osteogenesis imperfecta. The SEC24D-related disorder is inherited in an autosomal recessive manner. This means that if both parents have a variant in this gene and their children inherit both, the children display the disease.