Chester porphyria: a clinical study of a new form of acute porphyria.

Acute porphyria afflicts a large kindred in Chester that stems from a marriage in 1896 that has produced 200 descendants; this is the largest porphyric kindred to be identified in the United Kingdom. Six members aged 51 or under died from the condition over the past eight years. The diagnosis of porphyria was overlooked in some as the symptoms may mimic those of other acute illnesses, so that incomplete or incorrect death certificates have been issued. Psychosis, hypertension, and renal complications are particularly common. The porphyric members of the kindred show a previously undescribed hereditary disorder in which the characteristic enzymatic defects of acute intermittent porphyria and variegate porphyria coexist in the same subject. Acute porphyria is poorly understood by hospital and general practitioners, and this has caused anxiety in the kindred. A register of the kindred has been established, and families at risk should be offered biochemical screening, education, and genetic counselling.