The prenatal presentation of congenital erythropoietic porphyria: report of two siblings with elevated maternal serum alpha-fetoprotein.

Congenital erythropoietic porphyria (CEP), also termed Günther's disease, is extremely rare and is inherited as an autosomal recessive trait. The mutation that causes the most severe deficiency of the enzyme uroporphyrinogen III synthase (URO-synthase) is C73R. Inheritance of two abnormal alleles results in the accumulation of porphyrins of isomer type I that are biologically useless but cause a wide spectrum of abnormalities in multiple organs. The intrauterine diagnosis of the first affected conceptus within a family is extremely challenging despite abnormal ultrasound findings suggesting severe fetal anemia. We report the abnormal findings in a pair of successive pregnancies in a single Caucasian family that yielded two C73R homozygous affected offspring. The course of the pregnancies, sonographic and laboratory abnormalities, method used for intrauterine diagnosis, therapeutic interventions, and variability of outcome between cases within a single family and the difficulty in managing even prenatally diagnosed cases are reported and discussed. Copyright 2004 John Wiley & Sons, Ltd.