Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Craniometaphyseal dysplasia, autosomal recessive type ?
    ### Response:
    What causes autosomal recessive craniometaphyseal dysplasia? Autosomal recessive craniometaphyseal dysplasia is caused by mutations in the GJA1 gene. The GJA1 gene provides instructions for making a protein called connexin43, which is one of 21 connexin proteins in humans.
    