Thelansis

  A rare sub-group of porphyrias is characterized by the occurrence of neuro-visceral attacks with or without cutaneous manifestations. Acute hepatic porphyrias encompass four diseases: acute intermittent porphyria (the most common), variegate porphyria, hereditary coproporphyria, and hereditary deficit of delta-aminolevulinic acid dehydratase (extremely rare). Etiology- Each acute hepatic porphyria is a result of a deficiency of one of the enzymes in the heme biosynthesis pathway. These deficiencies result in an accumulation of the precursors of porphyrins in the liver (delta-aminolevulinic acid, ALA, and porphobilinogen, PBG) and also, in the case of variegate porphyria and hereditary coproporphyria, an accumulation of porphyrins resulting in cutaneous manifestations. Epidemiology- In the United States, the prevalence of porphyria is approximated to be one in 25,000 individuals.[6] The worldwide prevalence is approximated to range from one in 500 to one in 50,000 individu...