OMIM ID:
Cole-Carpenter Syndrome 2
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Postnatally the eyes are prominent and hypertelorism has been reported. The palpebral fissures slant downward and the root of the nose is angular.
Systemic Features
This is primarily a skeletal disorder with impaired skull ossification and multiple bone fractures of prenatal origin. It is sometimes confused with forms of osteogenesis imperfecta. The skull is poorly ossified and frequent diaphyseal fractures of the long bones occur leading to motor delays and short stature. Rib fractures are sometimes seen. Intelligence seems to be normal. A receding chin has been noted and the hard palate is highly vaulted. The midface is flat.
Genetics
Inheritance
This disorder results from compound heterozygous mutations in the SEC24D gene (4q26). Only a few patients have been reported.
For a somewhat similar but autosomal dominant disorder see Cole-Carpenter Syndrome 1 (112240).
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.