title: Mitochondrial DNA 4977 bp deletion is a common phenomenon in hair and increases with age.
abstract: Mitochondrial DNA (mtDNA) is believed to be particularly susceptible to oxidative damage during aging, resulting in mtDNA point mutations, duplications, and deletions. Although mtDNA deletions have been reported in various human tissues, e.g., the brain, heart, and skeletal muscle, little is known about the occurrence in hair. Therefore, we screened for the presence of mtDNA 13162 bp, 10422 bp, 7663 bp, 7436 bp, 4989 bp, and 4977 bp deletions in 90 hair samples from subjects aged 5 days to 91 years by using polymerase chain reaction (PCR) and investigated the deletion load by TaqMan probe-based real-time PCR. We detected the mtDNA 4977 bp deletion in hair samples, but none of the other deletions that were screened for. The proportion of mtDNA 4977 deletion carriers was 98.3% (89/90) and the deletion loads increased from 0 to 1.436 ± 0.2086% of the total mtDNA with an exponential increase with age (r = 0.677, p < 0.05). These results suggest that mtDNA 4977 bp deletion is a common phenomenon in hair and increases with age. These findings expand our understanding of the tissue-specific distribution of mtDNA deletions.
authors.affiliation: Department of Biochemistry and Molecular Biology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yijie
authors.initials: Y
authors.lastname: Zheng
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Luo
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zhu
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Yinting
authors.initials: Y
authors.lastname: Zhu
authors.forename: Huihua
authors.initials: H
authors.lastname: Cheng
authors.forename: Zhiqiu
authors.initials: Z
authors.lastname: Xia
authors.forename: Na
authors.initials: N
authors.lastname: Su
authors.forename: Nengpei
authors.initials: N
authors.lastname: Zhang
authors.forename: Junyi
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics*; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D004272:DNA, Mitochondrial / Q000235:genetics*; D006197:Hair / Q000737:chemistry*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction; D017384:Sequence Deletion; D055815:Young Adult
chemical_list: D004272:DNA, Mitochondrial