Below is an instruction from Human. Write a response.
    ### Instruction:
    What causes Alagille Syndrome ?
    ### Response:
    Alagille syndrome is caused by a gene mutation, or defect. Genes provide instructions for making proteins in the body. A gene mutation is a permanent change in the DNA sequence that makes up a gene. DNA, or deoxyribonucleic acid, is the material inside cells that carries genetic information and passes genes from parent to child.
    