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Science-Related Homework Help High School Level Science Topic started by: sycm on Nov 30, 2012



Title: Inheritance of a genetic disorder
Post by: sycm on Nov 30, 2012
Hypophosphatemia is a dominant genetic disorder caused by a deficiency of phosphates in the blood. Assuming the other parent is free of the disorder, males with the disorder will pass it on to all their daughters but not their sons, while females with the disorder will pass it on to approximately half of their children.

Draw Punnett squares to show the inheritance pattern of the disorder in each of the two scenarios.



Title: Re: Inheritance of a genetic disorder
Post by: Alexx on Nov 30, 2012
Since the probability for the disease to pass to male and female offsprings is different, the disease is X-linked.
If we symbolize by Xa the faulty chromosome and X the normal chromosome, then a male person with the disease has genotype XaY, while the normal male has XY.
A female person with the disease has genotype XaX (we assume that the person is heterozygous because the exercise mentions that "females with the disorder will pass it on to approximately half of their children."
A normal female person has genotype XX.

The punnett squares are at the attachment (red squares = children with the disease)


Title: Re: Inheritance of a genetic disorder
Post by: alpha don on Apr 8, 2013
this very helpful. i appreciate it :)