Observational Study of Acute Intermittent Porphyria Patients

Inclusion Criteria: * Patient's written consent to take part in the study after receiving all the information regarding the design, objectives and potential risks that may arise during the observational study; as well as general information about the subsequent clinical trial. * Age between 18 and 65 years, inclusively. * Patient diagnosed of AIP (by clinical, biochemical data and genetic confirmation of porphobilinogen deaminase (PBGD) gene mutation). The patient must have a severe AIP condition, with at least two hospitalizations during the previous year due to acute attacks (clinical manifestations of acute porphyria), or at least four hospitalizations during the previous year due to the requirement of hospital treatment administration (including day-hospital and home hospital program). * Ability to follow instructions and cooperate during the study conduct. Exclusion Criteria: * Pregnant women, positive urine pregnancy test, or intention of becoming pregnant. * Acute or chronic liver disease for viral, autoimmune or metabolic cause, gastrointestinal dysfunction (different from those typical gastrointestinal symptoms of an acute attack of AIP), kidney disorder (renal impairment defined as plasma creatinine \> 2 mg/dl (150 µmol/l)), severe respiratory disease, severe autoimmune disease or severe acute active infectious condition. * Presence of adeno-associated virus type 5 (AAV5) neutralizing antibodies. * Positive hepatitis B or C virus (HBV or HCV) serological test. * …