Question

Make pedigrees and punnett squares to determine if a mix-up had indeed occurred. Explain your determination.

CASE STUDIES IN GENETICS There are several different genes that code for different receptors on the surface of the e t allele is dominant to the Rh- allele. The Mand N alleles are co-dominant. ABO DI000 typing is an example of multiple alleles, where the A and B alleles are co-dominant while they are both dominant to the O allele. Smith and Ms. Jones gave birth to baby boys at the same time (named John and Tom respectively) on the same day in a large city hospital. After Ms. Smith took her baby home, she began to suspect that it was Ms. Jone's baby and that the hospital had somehow mixed the infants up. Blood tests revealed that Mr. Smith had blood type O, MN and Rh+; Ms. Smith had blood type B, N, Rh+; and John Smith had blood type B, M, Rh-. Mr. Jones had blood type A, M, Rh+; Ms. Jones had blood type AB, MN, Rh+; and Tom Jones had blood type O, MN, Rh+. Make pedigrees and punnett squares to determine if a mix-up had indeed occurred. Explain your determination.

Answer 1

KANSWER: . According to the enforemations provided, the of Smith - family, can be inforced as pedegree follows: I°T° MN Rht IB NN RA* _ John 1. IB_ MM RhRh. Given that M and N alleles are co-dominant, John Smith with m phenotype must be homozygous fere the gene beus ie mm: For this, he has to inherit a 'M' allele from each of the parents : which is not possible in this case, since his mother lacks the 'M' allele.

Also, the depicted podegree of Jones' as follows, according family to the can be informations preovided 1^ MM Rht IMIB MN Rit X Tom IT MN – Given that Tom has 'ö' blood group, he must be homoxygons for the gene lecer e I'I', for which he has the inherit an allele for Io from each of. his parents. However this is not possible since his mother lacks Io allele. Hence, it ean be inferred that a mix-up of babies has endeed occurred in the hospital! Now, the correct pedigrees of both the families can be represented as follows: Ch Jºgº MN RIERKY II NN RhRht Rhian Rht en Smith family : o IºIº MN Rheonty. Rht Rh

Jones - family Jones - famil or IAIO MM Rhah o I"IB MN Rhath John] IBI MN RhRh
By analysing the blood phenotypes of all the individuals mentioned in this case study, it can be inferred that a mixup of babies has indeed occurred in the hospital.