Other Factors That Could Indicate a Disability 
Developmental disabilities are birth defects related to a problem with how a body part or body system works. They may also be known as functional birth defects. Many of these conditions affect multiple body parts or systems. Researchers have identified thousands of different birth defects. Birth defects can have a variety of causes, such as:
  1. Genetic problems caused when one or more genes doesn’t work properly or part of a gene is missing,
  2. Problems with chromosomes, such as having an extra chromosome or missing part of a chromosome,
  3. Environmental factors that the expectant mother is exposed to during pregnancy, such as rubella or German measles or if she uses drugs or alcohol during pregnancy.
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