Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) hypohidrotic ectodermal dysplasia ?
    ### Response:
    Hypohidrotic ectodermal dysplasia is one of about 150 types of ectodermal dysplasia in humans. Before birth, these disorders result in the abnormal development of structures including the skin, hair, nails, teeth, and sweat glands.  Most people with hypohidrotic ectodermal dysplasia have a reduced ability to sweat (hypohidrosis) because they have fewer sweat glands than normal or their sweat glands do not function properly.
    