Could leukopenia cause reduction in height?

No. Leukopenia (white blood cells in the blood are fewer than normal) does not cause reduction a child's final height. However, if the leukopenia was severe, and the child had persistent or recurrent infections throughout childhood, he might not grow as tall due to having chronic illnesses. In an adult, leukopenia does not make him shorter.
No. leukopenia is a reduction in the number of leukocytes or WBC's. If below the 4000 level one is more susceptible to infection and not ht. reduction. The latter occurs when osteoporosis occurs in the vertebral bodies and there is a diminution in the height of the vertebrae.