Age-related mitochondrial DNA mutations in the human larynx.
OBJECTIVE
To determine whether age-related mitochondrial DNA mutations occur in the human larynx.


METHODS
Genetic study of cadaveric larynx specimens.


METHODS
Vocal fold mucosa, thyroarytenoid muscle, and cricoarytenoidjoint tissue were harvested from 13 fresh postmortem larynges (age range, 2 d-82 y). DNA was extracted from each sample, and the polymerase chain reaction (PCR) was used to amplify a target DNA sequence resulting from the common age-associated, 4977-base-pair (bp) mitochondrial DNA deletion. PCR products were visualized by agarose gel electrophoresis. Automated sequencing determined the sequence of identified PCR products.


METHODS
Thirteen cadaveric larynges were obtained through the University of Kentucky Medical Center (Lexington, KY). Specimens from patients with a history of head and neck cancer, previous laryngeal trauma, or surgery were excluded.


RESULTS
Strongly positive bands were identified in samples from three individuals. Weaker bands were seen in samples from four other samples. No band was noted from the two pediatric larynges. Different band patterns were seen among the three different tissue sites in the larynges with positive PCR products, but no consistent pattern was seen. Sequencing of the identified PCR products from selected samples confirmed that they were products of the age-associated, 4977-bp mitochondrial DNA deletion.


CONCLUSIONS
An age-associated mitochondrial DNA deletion was detected in several post-mortem human larynges. Its presence seemed to increase in appearance with age. In the larynges in which the deletion occurred, there were individual regional differences in the occurrence of the deletion, but no consistent pattern was noted across all individuals who carried the deletion.
Manaligod
J M
JM
Division of Otolaryngology--Head and Neck Surgery, University of Kentucky Medical Center, Lexington 40536, USA.
Milam
M
M
Hill
S A
SA
Sanders
T
T
Skaggs
J
J
Smith
R J
RJ
D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000235:genetics; D002872:Chromosome Deletion; D004272:DNA, Mitochondrial / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007830:Larynx / Q000502:physiology*; D008875:Middle Aged; D009154:Mutation; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
D004272:DNA, Mitochondrial