RT Book, Section
A1 Desnick, Robert J.
A1 Balwani, Manisha
A2 Kline, Mark W.
SR Print(0)
ID 1182930237
T1 Disorders of Heme Biosynthesis: The Porphyrias
T2 Rudolph's Pediatrics, 23e
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9781259588594
LK accesspediatrics.mhmedical.com/content.aspx?aid=1182930237
RD 2024/04/20
AB The  porphyrias  are  a  group  of  inherited  and  acquired  metabolic  disorders,  each  resulting  from  the  deficient  or  increased  activity  of  a  specific  enzyme  in  the  heme  biosynthetic  pathway.  These  enzyme  alterations  are  inherited  as  autosomal-dominant  or  -recessive  and  X-linked  traits,  with  the  exception  of  porphyria  cutanea  tarda  (PCT),  which  usually  is  sporadic.  These  disorders  are  classified  as  either  hepatic  or  erythropoietic,  depending  on  the  primary  site  of  overproduction  and  accumulation  of  the  porphyrin  precursor(s)  or  porphyrin(s)  (Table  162-1).  Clinically,  they  are  classified  as  acute  and  cutaneous,  although  some  have  overlapping  features.  Manifestations  of  the  acute  hepatic  porphyrias  are  primarily  neurologic,  including  severe  abdominal  pain,  neuropathy,  and  secondary  mental  symptoms,  whereas  the  erythropoietic  porphyrias  characteristically  cause  cutaneous  phototoxicity.