Fundamentals of Autosomal STR Typing for Forensic Applications: Case Studies

Key DNA profiling markers for identification: A mini review

“…In this light, the DNA, a threadlike structure is found in the nucleus of the human cell, tightly wound extensively around the histone proteins named chromosomes. 4,12 Archetypally, the chromosomes consist of two segments called arms which joins at a constriction point called the centromere. The two segments are regarded as the long and short arms of the chromosome represented by 'q' and 'p' arms respectively.…”

“…The human cell contains a pair of sex chromosomes and 22 pairs of autosomes, and based on distinctiveness, the prominent variation between the autosome and the sex chromosome is that, the former controls the sex and related individual traits, but the later regulates the somatic characteristics of a person. 4,13 Going forward, the twosex chromosome in humans are called allosomes, and it is chiefly responsible for the determination of an individual's sex. In this setting, the two humans sex chromosomes are represented as 'X' and 'Y' with the females containing two homomorphic copies of 'X' chromosome arranged in the same order, while males, carries a heteromorphic copies of sex chromosomes namely 'X' and 'Y' chromosomes.…”

“…In this setting, the two humans sex chromosomes are represented as 'X' and 'Y' with the females containing two homomorphic copies of 'X' chromosome arranged in the same order, while males, carries a heteromorphic copies of sex chromosomes namely 'X' and 'Y' chromosomes. 4,12 Forensic DNA profiling DNA Profiling also referred to as DNA fingerprinting, is a sequence of tests and methodology employed to examine and identify the genetic information contained within an individual's cell. 1 In the context of Forensics, Forensic DNA, a fortuitous byproduct of some of the most highly regarded, cutting-edge research in the scientific community, is regarded as the comparison of genetic information or profile of a person to a profile of biological evidence found at the scene of crime, or profile stored in the DNA database for the sole purpose of administration of justice.…”

“…3 The basis of DNA profiling/fingerprint is on the fact that every person has a unique set of genetic fingerprints that trails us, and this unique genetic fingerprint is a hereditary blueprint transmitted from parents to offspring. 4 The genetic information is stored in a molecule called the deoxyribonucleic acid (DNA), as a code made up of four nucleotide bases including: Adenine (A), Guanine (G), Cytosine (C), and Thymine (T) of which, adenine and guanine are regarded as double-ringed purines, while cytosine and thymine are regarded as single-ringed pyrimidines. 2 The target of most of the molecular markers in use for DNA profiling is reading the nucleotide sequences within the DNA of a person's cell.…”

“…Going forward, Short tandem repeats (STRs), also referred to as microsatellites, are short fragments of tandemly repeated DNA sequences of two to six base pairs in length found at a specific location in the chromosome mostly at center, called centromere. [4][5][6] At the specific chromosomal location, a locus is found to contain two allelic short tandem sequences of DNA transferred by each parent of an individual; Variable number tandem repeat (VNTRs) is also known as the minisatellite consisting of core repeated sequences of greater than six (> 6) mostly sequences of about (20-100 bases) repeated between 0 to 30 times. Minisatellites repeats are found in the genome organized as tandem repeats flanked by segments of non-repetitive sequences.…”