Hewakapuge Sudinna, van Oorschot Roland A H, Lewandowski Paul, Baindur-Hudson Swati
School of Molecular Sciences, Victoria University, Werribee Campus, P.O. Box 14428, MC, Melbourne, Vic. 8001, Australia.
Leg Med (Tokyo). 2008 Sep;10(5):236-42. doi: 10.1016/j.legalmed.2008.01.007. Epub 2008 Apr 18.
Currently DNA profiling methods only compare a suspect's DNA with DNA left at the crime scene. When there is no suspect, it would be useful for the police to be able to predict what the person of interest looks like by analysing the DNA left behind in a crime scene. Determination of the age of the suspect is an important factor in creating an identikit. Human somatic cells gradually lose telomeric repeats with age. This study investigated if one could use a correlation between telomere length and age, to predict the age of an individual from their DNA. Telomere length, in buccal cells, of 167 individuals aged between 1 and 96 years old was measured using real-time quantitative PCR. Telomere length decreased with age (r=-0.185, P<0.05) and the age of an individual could be roughly determined by the following formula: (age=relative telomere length -1.5/-0.005). The regression (R(2)) value between telomere length and age was approximately 0.04, which is too low to be use for forensics. The causes for the presence of large variation in telomere lengths in the population were further investigated. The age prediction accuracies were low even after dividing samples into non-related Caucasians, males and females (5%, 9% and 1%, respectively). Mean telomere lengths of eight age groups representing each decade of life showed non-linear decrease in telomere length with age. There were variations in telomere lengths even among similarly aged individuals aged 26 years old (n=10) and age 54 years old (n=9). Therefore, telomere length measurement by real-time quantitative PCR cannot be used to predict age of a person, due to the presence of large inter-individual variations in telomere lengths.
目前，DNA 分析方法仅能将嫌疑人的 DNA 与留在犯罪现场的 DNA 进行比对。当没有嫌疑人时，警方若能通过分析犯罪现场遗留的 DNA 来预测相关人员的外貌特征将会很有帮助。确定嫌疑人的年龄是绘制拼图人像的一个重要因素。人类体细胞的端粒重复序列会随着年龄增长而逐渐丢失。本研究调查了是否可以利用端粒长度与年龄之间的相关性，从个体的 DNA 来预测其年龄。使用实时定量 PCR 测量了 167 名年龄在 1 至 96 岁之间个体的口腔细胞中的端粒长度。端粒长度随年龄增长而缩短（r = -0.185，P < 0.05），个体年龄可通过以下公式大致确定：（年龄 = 相对端粒长度 -1.5 / -0.005）。端粒长度与年龄之间的回归（R²）值约为 0.04，该值过低，无法用于法医学鉴定。进一步研究了人群中端粒长度存在较大差异的原因。即使将样本分为非亲属的高加索人、男性和女性后，年龄预测准确率依然很低（分别为 5%、9%和 1%）。代表每个十年年龄段的八个年龄组的平均端粒长度显示，端粒长度随年龄呈非线性下降。即使在年龄相仿的 26 岁个体（n = 10）和 54 岁个体（n = 9）之间，端粒长度也存在差异。因此，由于个体间端粒长度存在较大差异，通过实时定量 PCR 测量端粒长度无法用于预测个体年龄。
