Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) monilethrix ?
    ### Response:
    Monilethrix is a condition that affects hair growth. Its most characteristic feature is that individual strands of hair have a beaded appearance like the beads of a necklace. The name monilethrix comes from the Latin word for necklace (monile) and the Greek word for hair (thrix).
    