Lineage marker as a key player in complex forensic cases from the perspective of Y chromosome

Abstract

Kako se Y hromozom kroz generacije ne menja rekombinacijama, prenosi se uglavnom nepromenjen sa oca na sina. Haplotipovi dobijeni kombinovanom analizom kratkih tandemskih ponovaka na Y hromozomu imaju široku primenu u forenzičkim analizama za definisanje paternalne linije muškog donora biološkog traga, posebno u slučajevima gde standardna analiza autozomnih markera nije dovoljno informativna. Y vezani haplotipovi se koriste i u evolucionim i genealoškim studijama, ali se za rekonstrukciju filogenije Y hromozoma koristi analiza polimorfizama pojedinačnih nukleotida. Promene na Y hromozomu se ipak dešavaju usled mutacija što može da dovede do diferencijacije Y vezanih haplotipova između oca i sinova. Tako mutacije u lokusima sa kratkim tandemskim ponovcima mogu da omoguće identifikaciju muškarca u okviru jedne paternalne linije, ali mogu i da dovedu do progrešnog isključenja biološkog srodstva. Usled toga je za tačnu interpretaciju genetičkih profila neophodna precizna procena stope mutacije pojedinačnih lokusa, za šta se koriste studije parova otac-sin ili velikih porodični stabala.Y chromosome is transmitted mostly unchanged from father to son due to the absence of recombination events. Haplotypes composed of Y-chromosomal short tandem repeat polymorphisms are widely used to define paternal line of unknown male perpetrator in forensic analysis, especially when standard analysis of autosomal markers is not informative enough. Y-chromosomal haplotypes are also used in evolutionary and genealogical studies, but single nucleotide polymorphisms are more suitable for the reconstruction of the Y chromosome phylogeny. However, Y chromosome changes due to mutations, which could lead to differentiation of Y haplotypes between father and sons. Thus, mutations in short tandem repeats loci can enable the identification of a man within a single paternal line, but they could also lead to an erroneous exclusion of biological paternity. Reliable mutation rates, for the proper use and accurate interpretation of genetic profiles, could be estimated from multi-generation pedigrees or father-son pairs