RT Book, Section
A1 Bissonnette, Bruno
A1 Luginbuehl, Igor
A1 Engelhardt, Thomas
SR Print(0)
ID 1164066340
T1 Complex I Deficiency
T2 Syndromes: Rapid Recognition and Perioperative Implications, 2e
YR 2019
FD 2019
PB McGraw-Hill Education
PP New York, NY
SN 9781259861789
LK accessanesthesiology.mhmedical.com/content.aspx?aid=1164066340
RD 2024/04/19
AB This  is  the  most  common  type  of  respiratory  chain  disease.  Complex  I  is  the  largest  respiratory  chain  complex  and  involved  in  numerous  clinical  conditions  (see  Table  C-1).  Forty-six  polypeptide  subunits  form  Complex  I,  of  which  seven  are  encoded  by  mitochondrial  DNA  (mtDNA)  and  the  residual  39  by  nuclear  DNA  (nDNA).  The  major  subunits  are  flavoprotein,  iron-sulfur  protein,  and  hydrophobic  fraction.  Complex  I  is  involved  in  the  electron  transport  from  NADH  to  ubiquinone,  from  where  the  electrons  are  transported  to  the  next  respiratory  chain  complex.  This  is  the  most  commonly  identified  respiratory  chain  disease  phenotype,  which  is  most  likely  related  to  the  large  number  of  subunits  encoded  by  both,  nuclear  and  mitochondrial  DNA  and  the  size  of  the  complex  subunit.  Complex  I  deficiency  is  often  part  of  a  combined  deficiency  because  deficiencies  in  other  complexes  may  result  in  a  loss  of  Complex  I  function.  It  is  the  result  of  a  number  of  situations  where  mtDNA  point  mutations  are  associated  with  deletions.  In  the  absence  of  known  mtDNA  abnormalities,  it  may  be  associated  with  fatal  infantile  encephalomyopathy.  As  an  isolated  deficit,  the  clinical  presentation  occurs  at  the  age  of  4  to  5  months  and  in  about  70%  of  patients  death  occurs  within  2  years.  Severe  lactic  acidosis  occurs  in  85%  of  patients.  Most  infants  also  present  with  severe  cardiomyopathy,  childhood  encephalopathy,  macrocephaly  with  progressive  leukodystrophy,  hepatomegaly,  and  real  tubulopathy.  The  most  frequent  myopathy  is  known  as  ☞MELAS  Syndrome.