Haplotype Analysis of Norwegian and Swedish Patients with Acute Intermittent Porphyria (AIP): Extreme Haplotype Heterogeneity for the Mutation R116W - Tjensvoll, Kjersti; Bruland, Ove; Floderus, Ylva; Skadberg, Øyvind; Sandberg, Sverre; Apold, Jaran (Disease Markers, 2003)