A young man claiming to be the son of Howard Hughes is suing the estate for his inheritance. Hughes (multimillionaire, inventor, businessman, and subject of the 2004 film, Aviator), did not leave behind any heirs upon his death. The judge overseeing this case, orders blood tests. Howard Hughes has blood type AB, the mother of the young man has type A blood, and the young man had type O. If you were the judge in this case, what would be your ruling?

The human blood system works on codominance type of inheritance in the case of blood group A and blood group B present together however, in blood group O it still follows the law of dominance as antigen O is recessive in present of any other antigen.

We know Howard Hughes had blood type AB

So, the genotype would be - IAIB

We also know that the mother of the young man claiming has a blood type A

So, possible genotypes would be - IAIA (case 1) or IAi (case 2)

For case 1,

The possible genotypes for the man claiming would be

IAIB X IAIA --------> IA IA, and IAIB.

According to case 1, he is not the son of Howard.

For case 2,

The possible genotypes for the man claiming would be

IAIB. X I A i ---------> IA IA , IAIB I A i and IB i

Both cases show that the man claiming is not the son of Howard as the blood group of the man is O and the genotype should be ii.