Department of Diagnostics and Public Health, Unit of Forensic Medicine - Forensic Genetics Laboratory, University of Verona, Italy.
Med Sci Law. 2021 Jan;61(1_suppl):62-66. doi: 10.1177/0025802420922335.
Monozygotic twins, also known as monovular twins, share an identical genetic heritage because they are two individuals who derive from the same zygote. For this reason, they have been considered indistinguishable. They represent a limit for the application of markers and analytical methods that are routinely used in forensic science because analyses of DNA fragments (short tandem repeats analysed by capillary electrophoresis) are unable to distinguish monozygotic twins. The recent introduction of ultra-deep next generation sequencing in forensic genetics, also known as massively parallel sequencing, has made it possible to identify a number of genetic variations through genome sequencing (such as copy number variations, single nucleotide polymorphisms and DNA methylation) that make it possible to distinguish monozygotic twins. Here, we present a case of ascertaining biological paternity, in which the alleged father had a monozygotic twin brother. This case led to the examination of international law in similar cases in which the only available biological evidence derives from classical forensic genetic analysis, performed with short tandem repeat (autosomal and/or gonosomal) capillary electrophoresis and the probative value, if recognised, of the next generation sequencing technology in the courtroom.
同卵双胞胎，也被称为单卵双胞胎，具有相同的遗传基因，因为他们是由同一个受精卵发育而来的两个个体。出于这个原因，他们被认为是无法区分的。他们代表了在法医学中常用的标记和分析方法的应用极限，因为 DNA 片段的分析（通过毛细管电泳分析的短串联重复）无法区分同卵双胞胎。最近在法医遗传学中引入的超高深度下一代测序，也称为大规模平行测序，通过基因组测序（如拷贝数变异、单核苷酸多态性和 DNA 甲基化）可以识别出许多遗传变异，从而能够区分同卵双胞胎。在这里，我们介绍了一个确定生物学亲子关系的案例，在这个案例中，被指控的父亲有一个同卵双胞胎兄弟。这个案例导致了对类似案件中的国际法的审查，在这些案件中，唯一可用的生物证据来自经典的法医遗传学分析，使用短串联重复（常染色体和/或性染色体）毛细管电泳进行分析，以及下一代测序技术在法庭上的证据价值（如果被认可的话）。
