1 Genetics

• Allele is a gene at a particular locus that differs in their nucleotide sequence.
• Polymorphic refers to having two or more possible alleles at a locus.
• Rect/secondary exclusion occurs when a single marker is detected in the child and a different single marker is detected in the alleged father.
• Allelic is one of two or more different genes that may occupy a specific locus on a chromosome.
• Antithetical refers to the opposite form of a gene, different allele or opposite antigens encoded at the same locus.
• Genotype is the total genetic composition of an individual which can be detected using molecular methods.
• Phenotype is the detectable or expressed characteristics of a gene which can be detected using serotyping.
• Gregor Mendel is the father of genetics.
• Mendelian genetics refers to genes that occur in pairs, one gene is passed from parent to the offspring.
• Under Mendelian inheritance, there are two laws: the Law of Independent Segregation and the Law of Independent Assortment.
• Missense mutation results in a change in a codon, which alters the amino acid in the corresponding peptide.
• Yves Lapierre is known for his work in gel technology.
• Point mutation is the simplest type of mutation, in which only one nucleotide in the DNA sequence is changed.
• Transversion is a type of mutation in which purine is substituted for a pyrimidine or a pyrimidine for a purine.
• These changes cannot be accommodated by the peptide while still maintaining its function.
• Mutation is a change in the structure or sequence of DNA, whether it is physical or biochemical.
• Point mutations include substitutions, insertions, and deletions.
• Transition is a type of point mutation where one purine is substituted for another purine, or one pyrimidine is substituted for another pyrimidine.
• Charles Drew is the Father of modern blood banking.
• The Law of Independent Segregation states that the parental genes must separate randomly and equally into gametes so there is an equal chance of the offspring inheriting either allele.
• The Law of Independent Assortment states that genes for different traits are inherited separately from each other.
• Heterozygous refers to an individual inheriting different alleles at the same gene locus from each parent.
• Agglutination reactions are generally stronger for homozygous than in heterozygous cells due to the higher number of antigens expressed in homozygous cells than in heterozygous cells.
• Karl Landsteiner discovered ABO blood group in 1914.
• Gibson introduced Citrate phosphate dextrose as blood preservative in 1957.
• Braxton, Hicks introduced the use of sodium phosphate/phosphate soda as blood preservative in 1869.
• Edward Lindemann carried out vein to vein transfusion in 1901.
• Punnett squares are useful for understanding inheritance of blood groups and ramification of heterozygosity or homozygosity.
• Inheritance allows for all possible combinations of genes to occur in the offspring.
• Homozygous refers to an individual inheriting identical (the same) allele at the same gene locus from both parent.
• Albert Hustin determined the minimum concentration of citrate as anticoagulant in 1915.
• The inheritance pattern of blood group antigens can be predicted using Punnett square.
• Pope Innocent VII performed the 1st recorded blood transfusion in 1492.
• Loutit and Mollison introduced Acid citrate dextrose as preservative in 1943.
• Recombination mutations involve recombination or crossing over during the process of meiosis in the formation of gametes.
• Mismatch is used when the bands between the child and the alleged father do not match, and reporting of mismatch requires at least two mismatches before reporting nonpaternity/nonmaternity.
• Frameshift mutation results in a nonfunctional transferase protein that is seen phenotypically as the O blood group.
• Genetic system used in parentage testing includes RBC antigens, RBC enzymes and proteins, DNA polymorphism, Immunoglobulin allotypes, and Human leukocyte antigens.
• Amorph gene does not produce any obvious, easily detectable traits and is seen only at the phenotypic level when the individual is homozygous for the trait.
• Interpretation of results includes W-value, which is the likelihood of paternity; it must be 95% to suggest paternity.