Amelogenin Gene - The Pioneer in Gender Determination from Forensic Dental Samples

Abstract

Introduction: In the event of any mass fatality incident, DNA analysis plays a vital role in disaster victim identification. Teeth are one of the most resistant structures in the human body that resist decomposition hence making them prime choice for extracting DNA for identification of individuals. Polymerase Chain Reaction (PCR) analysis that target regions of Amelogenin gene have become the method of choice for sex determination of biological samples.

Aim: Determining the sex of a given DNA sample from either dental pulp or dentin of tooth and help in identification of missing persons and disaster victims.

Materials and methods: In our study 50 teeth samples were studied and they were subjected to various environmental conditions along with freshly extracted teeth taken as control for duration of one month and three months. Pulpal tissue was retrieved from the teeth specimens by access opening of root canals and for incinerated samples, the specimens were crushed. From the DNA that was extracted from the dental pulp sample Amelogenin gene locus was used for sex determination by amplifying a segment of X-Y homologous gene locus through PCR analysis.

Results: ANOVA test and t-test proved to be statistically significant and 100% retrieval rate was observed in samples.

Conclusion: Pulpal tissue along with degenerating odontoblastic processes yield sufficient amount of DNA for gender determination when subjected to various forensic conditions with maximum accuracy.

Keywords: Forensic odortology; Incineration; Mass fatality; Polymerase chain reaction.

[Table/Fig-2-4]:

Excavating dental pulpal tissue from freshly extracted non-carious teeth by access opening.

[Table/Fig-5,6]:

Teeth samples subjected to incineration at 800^OC, 1050^OC.

[Table/Fig-7]:

Incinerated sample freshly taken out of the incinerator at 950^oC in a crucible.

[Table/Fig-9]:

Genomic DNA isolated from dental pulp samples were loaded on 1% agarose gel.

[Table/Fig-10]:

Amelogenin PCR products were loaded on 0.8 % agarose gel. Male: two band at ~ 1.3 kilobase (kb) {Lane 4,5} and 1.5 kb. Female: Single band at 1.5 kb {Lane 1,2,3}.

[Table/Fig-14]:

Distribution of No. of PCR cycles by categories (% analysis).