title: Application of Short Tandem Repeat markers in diagnosis of chromosomal aneuploidies and forensic DNA investigation in Pakistan.
abstract: OBJECTIVE
  Short Tandem Repeat (STR) genetic markers hold great potential in forensic investigations, molecular diagnostics and molecular genetics research. AmpFlSTR® Identifiler™ PCR amplification kit is a multiplex system for co-amplification of 15 STR markers used worldwide in forensic investigations. This study attempts to assess forensic validity of these STRs in Pakistani population and to investigate its applicability in quick and simultaneous diagnosis and tracing parental source of common chromosomal aneuploidies.
  
  
  METHODS
  Samples from 554 healthy Pakistani individuals from 5 different ethnicities were analyzed for forensic parameters using Identifiler STRs and 74 patients' samples with different aneuploidies were evaluated for diagnostic strengths of these markers.
  
  
  RESULTS
  All STRs hold sufficient forensic applicability in Pakistani population with paternity index between 1.5 and 3.5, polymorphic information content from 0.63 to 0.87 and discrimination power ≥0.9 (except TPOX locus). Variation from Hardy-Weinberg equilibrium was observed at some loci reflecting selective breeding and intermarriages trend in Pakistan. Among aneuploidic samples, all trisomies were precisely detectable while aneuploidies involving sex chromosomes or missing chromosomes were not clearly detectable using Identifiler STRs. Parental origin of aneuploidy was traceable in 92.54% patients.
  
  
  CONCLUSIONS
  The studied STR markers are valuable tools for forensic application in Pakistan and utilizable for quick and simultaneous identification of some common trisomic conditions. Adding more sex chromosome specific STR markers can immensely increase the diagnostic and forensic potential of this system.
authors.affiliation: Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan; Institute of Biomedical and Genetic Engineering, Islamabad, Pakistan.
authors.forename: Hafsah Muhammad
authors.initials: HM
authors.lastname: Chishti
authors.affiliation: Department of Biochemistry, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ansar
authors.affiliation: Institute of Biomedical and Genetic Engineering, Islamabad, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ajmal
authors.affiliation: Institute of Biomedical and Genetic Engineering, Islamabad, Pakistan. Electronic address: ahameed0786@hotmail.com.
authors.forename: Abdul
authors.initials: A
authors.lastname: Hameed
mesh_terms: D025063:Chromosome Disorders / Q000235:genetics*; D005006:Ethnicity / Q000235:genetics; D005260:Female; D053803:Forensic Genetics; D005787:Gene Frequency; D005819:Genetic Markers; D006801:Humans; D007621:Karyotyping; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D010154:Pakistan; D057089:Pathology, Molecular; D014314:Trisomy
chemical_list: D005819:Genetic Markers
keywords: Forensic; Identifiler; Karyotyping; Pakistan; Short Tandem Repeats; Trisomy