Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Rothmund-Thomson syndrome ?
    ### Response:
    Rothmund-Thomson syndrome is a rare condition that affects many parts of the body, especially the skin. People with this condition typically develop redness on the cheeks between ages 3 months and 6 months. Over time the rash spreads to the arms and legs, causing patchy changes in skin coloring, areas of thinning skin (atrophy), and small clusters of blood vessels just under the skin (telangiectases).
    