Concordance: It is measure of % single nucleotide polymorphism (SNPs) are identical for positions of variance and is used to detect SNPs in genetic assaying. Single nucleotide polymorphism (SNP) occurs due to the difference in a single nucleotide at a specific site. SNP is a site in the genome with a base-pair difference among chromosomes that is present at least one in every 50 individuals due to inheritance by descent. Therefore, in the above case, for epilepsy, you find that monozygotic concordance rates are 69% but only 5% for dizygotic twin pairs. Identical twins theoretically possess a concordance (presence of same trait in both twins) rate of 100%. Hence these two traits of \"epilepsy (MZ --> 69%), osteoarthirtis (MZ --> 31%)\" has a greater genetic contribution in monozygotic twins due to greater identical existence of SNPs in monozygotic twins Solution Concordance: It is measure of % single nucleotide polymorphism (SNPs) are identical for positions of variance and is used to detect SNPs in genetic assaying. Single nucleotide polymorphism (SNP) occurs due to the difference in a single nucleotide at a specific site. SNP is a site in the genome with a base-pair difference among chromosomes that is present at least one in every 50 individuals due to inheritance by descent. Therefore, in the above case, for epilepsy, you find that monozygotic concordance rates are 69% but only 5% for dizygotic twin pairs. Identical twins theoretically possess a concordance (presence of same trait in both twins) rate of 100%. Hence these two traits of \"epilepsy (MZ --> 69%), osteoarthirtis (MZ --> 31%)\" has a greater genetic contribution in monozygotic twins due to greater identical existence of SNPs in monozygotic twins.