Aceruloplasminemia with Novel Mutation, with IgG4 Related Pachymeningitis - Occam's Razor or Hickam's Dictum?

To report a patient with concomitant aceruloplasminemia (with a novel mutation) and IgG4-related pachymeningitis and to hypothesize on the possible relation between the two diseases. Clinical, radiological, and laboratory features of a 56-year-old lady with chronic headache, bifacial palsy, and cerebellar signs are described. Pathophysiology of aceruloplasminemia leading to hyperferritinemia and consequent immune activation is elucidated. A coherent explanation of IgG4-related pachymeningitis resulting from aceruloplasminemia and hyperferritinemia is given. The patient has aceruloplasminemia with a novel nonsense mutation. She also suffers from biopsy-proven IgG4 related pachymeningitis as per standard criteria. These two seemingly unrelated illnesses are linked by hyperferritinemia. This case is a fine example of Occam's razor. Immune dysfunction and autoimmune disorders in aceruloplasminemia need to be explored through further studies to look for causal associations.