ANKRD11

KBG syndrome

Several ANKRD11 gene mutations have been found to cause KBG syndrome, a condition characterized by large upper front teeth and other unusual facial features, skeletal abnormalities, and intellectual disability. Most of these mutations lead to an abnormally short ANKRD11 protein, which likely has little or no function. Reduction of this protein's function is thought to underlie the signs and symptoms of the condition. Because ANKRD11 is thought to play an important role in neurons and brain development, researchers speculate that a partial loss of its function may lead to developmental delay and intellectual disability in KBG syndrome. However, the mechanism is not fully known. It is also unclear how loss of ANKRD11 function leads to the skeletal features of the condition.

Another type of mutation that affects the ANKRD11 gene, called 16q24.3 microdeletion, deletes genetic material from chromosome 16 in a region designated q24.3. The deleted region typically removes the ANKRD11 and ZNF778 genes, although other nearby genes may also be affected. People with this type of mutation have similar signs and symptoms to those of KBG syndrome, including unusual facial features and intellectual disability. Many also have brain abnormalities and features of autism spectrum disorders, which are characterized by impaired communication and socialization skills. Some researchers think that these microdeletions are different enough from KBG syndrome to be considered a separate disorder, called 16q24.3 microdeletion syndrome.