RT Book, Section
A1 Calado, Rodrigo T.
A1 Young, Neal S.
A2 Jameson, J. Larry
A2 Fauci, Anthony S.
A2 Kasper, Dennis L.
A2 Hauser, Stephen L.
A2 Longo, Dan L.
A2 Loscalzo, Joseph
SR Print(0)
ID 1156521774
T1 Telomere Disease
T2 Harrison's Principles of Internal Medicine, 20e
YR 2018
FD 2018
PB McGraw-Hill Education
PP New York, NY
SN 9781259644016
LK accessmedicine.mhmedical.com/content.aspx?aid=1156521774
RD 2024/04/19
AB In  telomere  diseases  (also  called  telomeropathies  or  telomere  spectrum  disorders),  organ  dysfunction  is  caused  by  loss  of  the  ends  of  chromosomes,  a  process  termed  accelerated  telomere  attrition.  Inadequate  repair  or  insufficient  protection  of  telomeres  and  their  resulting  erosion  induces  cell  death,  deficient  cell  proliferation,  and  chromosome  instability;  affected  tissues  show  defective  organ  regeneration,  fibrosis  or  replacement  by  fat,  and  a  proclivity  for  cancer.  A  variety  of  regenerative  disorders  affecting  especially  the  bone  marrow,  lungs,  liver,  and  skin  share  telomere  dysfunction  and  loss  as  their  common  molecular  mechanism.  It  is  important  to  note  that  telomeres  appear  to  shorten  with  time  based  on  cross-sectional  data  of  average  telomere  length  in  groups  of  people  at  different  ages.  However,  limited  data  exist  about  telomere  shortening  longitudinally  in  individual  people.  Despite  shortening  of  telomeres  over  time,  normal  aging  is  not  associated  with  the  development  of  disease  from  short  telomeres.  In  normal  aging,  sufficient  stem  cell  number  and  function  are  maintained  to  sustain  vital  processes.  Even  a  patient  who  receives  a  limited  number  of  hematopoietic  cells  from  an  adult  donor  is  capable  of  maintaining  normal  hematopoiesis  for  many  years,  at  least  in  part  related  to  normal  telomerase  function  and  telomere  repair.  When  symptoms  develop  as  a  consequence  of  short  telomeres,  a  disease  process  is  at  work.