Porphyrins, porphyrin metabolism and porphyrias. II. Diagnosis and monitoring in the acute porphyrias

The acute porphyrias constitute a group of metabolic disorders engaging enz ymes in the haem synthetic chain and generally following dominant inheritan ce patterns. Some gene carriers are vulnerable to a range of exogenous and endogenous factors, which may trigger neuropsychiatric symptoms. Early diag nosis is of prime importance since it makes way for counselling with the ai m to block the development of acute, as well as late, disease. The medical and psyche-social consequences of a porphyria diagnosis are considerable an d the freedom for maldiagnosis correspondingly small. The strain imposed up on the diagnostic process makes management in specialized laboratories nece ssary. Inadvertent handling of the diagnostic procedures in laboratories la cking in knowledge, experience and technical competence is repeatedly the r eason for harmful underdiagnosis and overdiagnosis. Gene diagnosis of the c arrier condition, principally within reach in all types of acute porphyria, is of incomparable versatility and accuracy. However, despite recent great -achievements in the molecular biology of porphyric disease, genomic proced ures cannot replace biochemical methods in monitoring the activity and prog ress of the disease, or the effects of therapy. The classical methods are a lso useful when it comes to screening for the associated disease states. In these tasks, professional handling of the methods and skilful interpretati on of the results are of paramount importance. Knowledge of the limitations and pitfalls of the procedures is a guard against maldiagnosis, which may be fatal. In the article the main diagnostic challenges are discussed; the strategy for early detection of the gene carrier state, the recognition and surveillance of the acute porphyric crisis, the evaluation of subacute/sub chronic symptoms, the differential diagnoses of the cutaneous porphyrias an d the monitoring of late complications.