Parentage Analysis with GenoProof
GenoProof accompanies the complete parentage investigation workflow from analysis of sequencer raw data to conduction of biostatistical calculations and generation of reports and expertise.
The software determines all important parameters for standard trio and duo constellations and even for unusual scenarios like deficiency cases and incest cases. Furthermore, you can conduct sibling analyses, monozygoty tests and avuncular tests. Family trees enable the visualization of family relations. To comply with ISFG guidelines, in GenoProof you can consider different mutation models (RFLP, AABB or Step model), silent alleles, subpopulation and linkage groups in your calculations. Additionally, rare alleles and linked markers can be taken into account.
Following you will find an overview of all calculations for parentage analysis:
Kinship Analysis
Kinship analyses calculate the probability of two persons having a certain degree of kinship. The algorithm determines the probability of two persons having a certain genotype combination in case of a particular degree of relation. Weir (1996) distinguishes five different degrees of relationship:
- Full sibling
- Parent and child
- Half sibling, grandparents and child or aunt/uncle and nephew/niece
- First cousins
- Unrelated persons
Duo and Trio Cases
Paternity tests aim to include or exclude a man (alleged father) as the biological father of a child or analogously include or exclude an alleged mother as the biological mother. Based on the probability W the program displays a rating of paternity probability (Hummel, 1997). Additionally, the program calculates paternity indexes (PI), Essen-Möller values (EM) and power of exclusion (PE).
Paternity and Maternity Tests with Grandparents
In case of no available genetic information for a parent or alleged parent, paternity tests can be conducted using information of the corresponding grandparents. Thereby, the program supports all possibilities: mother, father or both parents can be replaced by the referring grandparents. The test can be conducted one-sided or both-sided considering the paternal, maternal or both sides.
Complex Kinship Examinations
In more complex questions such as deficiency caseswith untyped probands, special calculations are necessary. For it, GenoProof is using the combinatorial deficiency analysis (Conradt) for the determination of all possible pedigree constellations and the kinship algorithm (Ihm and Hummel) for the calculation of genotypical pedigree likelihoods. Thus, the user has the opportunity to freely define any possible null hypothesis and alternative hypothesis.
Paternity Tests in Cases of Incest
If close relatives are supposed to be parents of a child, alternative calculation formulae are used for calculation of paternity indexes.
Calculation of the Avuncular Index
To determine the probability of an alleged father being the brother of the biological father you can calculate the avuncular index.
Probability of Monozygoty of Twins
Knowing the zygoty (monozygotic or dizygotic) of twins can be important for medical, scientific and personal reasons. Therefore, you can calculate the probability of two twins with the same genotype being monozygotic or dizygotic.
X- and Y-chromosomal Comparison
X- and Y-chromosomal comparisons are based on the sex-specific inheritance of gonosomal markers.
Thus, the X-chromosome of men does always originate from mother, while women inherit one X-chromosome from each parent. Since only men carry Y-chromosomes, the Y-chromosomes are always passed by the father.
Population Studies
With GenoProof you can conduct and evaluate population studies. Based on the genotypes of persons of a population, allele frequencies and other parameters can be determined. The calculated parameter can be integrated in your reference database and used for parentage analyses.
The program determines the following statistical parameters for all investigated STR loci:
- Allele frequencies
- Genotype frequencies
- Polymorphic information content (PIC)
- Homozygoty (h) und heterozygoty (HET)
- Power of exclusion (PE) (for each marker and for the whole study)
- Paternity index (PI) (for each marker and for the whole study)
- Power of discrimination (PD) (for each marker and for the whole study)
- Mean chance of exclusion (MEC)
- Gene diversity (GD) (for Y-chromosomal markers)
- Hardy-Weinberg equilibrium (asymptotic and as exact test)
Thereby, an unlimited number of samples can be used for each study and you can combine autosomal and gonosomal markers in one study. Additonally to calculation results, allele and genotype frequencies can be displayed as charts. All results can be exported or used for generation of reports. You can also share them with other users of GenoProof as for scientific cooperation reasons.