Preliminary immunological studies in spinal muscular atrophy.

Evidence of impaired cell-mediated immunity in children with spinal muscular atrophy was obtained using lymphocyte transformation with PHA (20 children) and skin tests with tuberculin and DNCB (35 children). Laryngological examination of 16 children demonstrated hypoplasia of lymphatic tissue in Waldeyer's ring and the cervical lymph nodes. An ectodermal defect involving both spinal cord and thymus is suggested.