1) The document discusses various blood grouping systems including ABO, MN, and Rh, and their application in determining disputed paternity, identifying blood stains, and inheritance claims. 2) It explains the basic genetic principles of alleles, genotypes, and phenotypes and how blood groups are inherited according to Mendel's laws of heredity. 3) The efficacy of different blood grouping systems in excluding paternity ranges from 16% for ABO grouping to nearly 100% for DNA profiling.

1. Blood grouping & Paternity
Testing
Toxicology & Forensic Serology 1
Dr. Aamir Ali Khan
Assistant Professor
PhD Biochemistry

2. Blood Grouping
• The RBC’s of men/mammalsarecircular,bioconcave & non
nucleated (camels are exceptions)
• Birds, fish&reptilesRBC’s areoval& nucleated
• RBC’s contains
– 65%water
– 35 %Solid
» Of which33% ishemoglobin
» 2%mixture of protein, blood group,cholesteroletc

3. Application of Blood Group in Forensic
Toxicology & Forensic Serology 3
• The applicationof blood group determination for medico
legalproblems isdone for following purpose
– Disputed paternityandmaternity
– Todeterminepossiblesource of blood staine.g. murder, rape
etc
– Inheritance claim
– Rh hazard
– Transfusion error

4. Basic GeneticPrincipal
5/22/2021 Toxicology & Forensic Serology 4
• Genes the hereditary factor present in every cell
• Genes present inpairsknow alleles/Allelomorphs
– Alleles are pairof contrasting genesone from eachparent
– Iftwo genesidentical-homozygous
– iftwo genesdifferent-heterozygous
• Organismjudgedbycharacter- Phenotype e.g.Blood GroupA
• Organismgeneticmakeup-genotype e.g.GroupA maybe
AO/AA

5. Blood Group As Hereditary Factor
5/22/2021 Toxicology & Forensic Serology 5
• The various blood group system (ABO,MN,Rh etc) its
inheritance based on two principal
– First: the groupand its characteristics develop atearlyage,
specificto individual&unchangedthroughout life
– Second: the characteristic of antigeninheritedas per
Mendel’s Laws ofHereditary

6. ABO System and Paternity
Toxicology & Forensic Serology 6
• AgglutinogenA (A1,A2) or Bcannot appearinchild until
present inboth or one of theparents
• An O parent canthaveAB childandvice versa
• Iftwo both parents of genotypeAO , achildmay born
with O group

7. Exclusion of paternity on theABO system
Toxicology & Forensic Serology 7

8. M N Blood System
Toxicology & Forensic Serology 8
• The MN blood group system is under the control of an autosomal locus
found on chromosome 4, with two alleles designated LM and LN. The
blood-type is due to a glycoprotein present on the surface of red blood
cells, which behaves as a native antigen.
• AgglutinogenMor N alwaysappearinbloodofchild
• TwoMparentscanthaveN childandviceversa
• Ifone parentistype Mandother TypeN thenallchildren aretypeMN
• Ifone parentishomozygous(Mor N) andother heterozygous thenallchildren
having50,50ratioto parental types
• IfbothparentsareMNtype thenchildrenof allthree types possible

9. Rh System
Toxicology & Forensic Serology 9
• Rh negativeparents cannot produce Rhpositive child
• Rhpositive homozygous parents canthaveaRh
negative children
• Rhpositive heterozygous parents canproduce both Rh
positive andRhnegative parents

10. Other bloodcomponent
1
0
5/22/2021 Toxicology & Forensic Serology
• Groupingbasedonbloodprotein
– Haptoglobin(Haptoglobin is an acute phase protein capable of binding
hemoglobin, thus preventing iron loss and renal damage. Haptoglobin
also acts as an antioxidant, has antibacterial activity and plays a role in
modulating many aspects of the acute phase response)
– Hemoglobintypesetc
• Groupingbasedonenzymes
– Phosphoglucomutase(Phosphoglucomutase(PGM)(EC5.4.2.21)isanevolutionarily
conservedandwellcharacterizedenzymethatcatalyzestheinterconversionofglucose1-
phosphateandglucose6-phosphateviaaglucose1,6-diphosphateintermediate,makingita
keyenzymeinbothglycolysisandgluconeogenesis).
• Groupingbasedonwhitecellantigen
• Humanleucocytes antigen (HLA)

11. Efficacy of DifferentSystem
1
1
5/22/2021 Toxicology & Forensic Serology
Group
• ABO grouping system
• MN system
• Rhsub groups
• HLA system
• DNA profiling
Exclusion of Paternity
16 %
33 %
50%
90 %
100 %

12. Case of Disputed paternity
1
2
Toxicology & Forensic Serology
• Alleged father AB, mother O, Child O, what isyour
thoughtsof paternity?
• Alleged FatherA, mother O, Child AB, isthat issue of
paternity or maternity?

13. Reference
1
3
Toxicology & Forensic Serology
• Text book of MedicalJurisprudence,ForensicmedicineandToxicology,BV
SubrahmanymSeventhedition.