ZIC1-related craniosynostosis is caused by single mistake, or mutation, within the ZIC1 gene. Genes are like instructions, telling the body how to grow and develop. Each gene (a small piece of our DNA, the genetic code) is an instruction to assemble a protein. Proteins are made up of building blocks called amino acids and are important for the formation and proper functioning of our body. If you think about the ZIC1 gene as the letters in a sentence (coding for the protein) with words equivalent to amino acids, then a single letter change can alter the meaning by changing the amino acids within the protein (known as missense mutations) or by shortening the length of the protein (known as nonsense mutations) or even by lengthening the protein. These types of changes in the ZIC1 gene are thought to lead to the abnormal functioning of the ZIC1 protein, which in turn leads to the clinical features.
ZIC1 is thought to be important for normal brain development and function, as well as for correct formation of the skull. Disturbances in these processes lead to the intellectual disability and the craniofacial characteristics of ZIC1 patients. However, the range of clinical features associated with having a ZIC1 mutation is still not fully understood.
ZIC1