Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Holt-Oram syndrome ?
    ### Response:
    Holt-Oram syndrome is characterized by skeletal abnormalities of the hands and arms (upper limbs) and heart problems.  People with Holt-Oram syndrome have abnormally developed bones in their upper limbs. At least one abnormality in the bones of the wrist (carpal bones) is present in affected individuals.
    