CD79A and hereditary spastic paraplegia: According to the last endorsed criteria by the EULAR/PINTO/PRES and American College of Rheumatology (ACR) the HSP diagnosis requires the presence of the palpable purpura and at least one of the following: arthritis or arthralgia, diffuse abdominal pain, renal involvement with haematuria and/or proteinuria or any biopsy showing predominant IgA deposition [2–4].