RT Book, Section
A1 Kishnani, Priya S.
A1 Chen, Yuan-Tsong
A2 Rudolph, Colin D.
A2 Rudolph, Abraham M.
A2 Lister, George E.
A2 First, Lewis R.
A2 Gershon, Anne A.
SR Print(0)
ID 6726312
T1 Chapter 156. Disorders of Pentose Phosphate Pathway
T2 Rudolph's Pediatrics, 22e
YR 2011
FD 2011
PB The McGraw-Hill Companies
PP New York, NY
SN 978-0-07-149723-7
LK accesspediatrics.mhmedical.com/content.aspx?aid=6726312
RD 2024/04/25
AB PEPCK  is  a  key  enzyme  in  gluconeogenesis.  It  catalyzes  the  conversion  of  oxaloacetate  to  phosphoenolpyruvate.  PEPCK  deficiency  has  been  described  both  as  a  mitochondrial  (OMIM  261650)  and  as  a  cytosolic  (OMIM  261680)  enzyme  deficiency,  encoded  by  two  distinct  genes.  The  disease  has  been  reported  in  only  a  few  cases  all  are  questionable,  with  no  molecular  confirmation.  The  clinical  features  are  heterogeneous,  with  hypoglycemia,  lactic  acidemia,  hepatomegaly,  hypotonia,  developmental  delay,  and  failure  to  thrive  as  the  major  manifestations.  Hepatic  and  renal  dysfunction  may  be  present.  The  diagnosis  is  based  on  the  reduced  activity  of  PEPCK  in  liver,  fibroblasts,  or  lymphocytes.  Fibroblasts  and  lymphocytes  are  not  suitable  for  diagnosing  the  cytosolic  form  of  PEPCK  deficiency,  because  these  tissues  possess  only  mitochondrial  PEPCK.  To  avoid  hypoglycemia,  patients  should  be  treated  with  slow-release  carbohydrates  such  as  cornstarch,  and  fasting  should  be  avoided.