In our case, despite negative DIF for IgA, the patient met the European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR) criteria for HSP, which require clinical findings of lower extremity purpura in addition to one of the following symptoms: abdominal pain, histopathology-confirmed IgA deposition, arthralgias, age less than 20 years at onset, LCV confirmed by biopsy, or renal involvement [12,14]. The gene discussed is CD79A; the disease is hereditary spastic paraplegia.