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What is the mode of inheritance?Moderator: BioTeam
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What is the mode of inheritance?In humans, there is a genetic disease called Hypophosphatemia that causes rickets. Here is a list of the phenotypes of the parents and their offspring from four different marriages.
Marriage #1: Mother phenotype: Healthy Father phenotype: Rickets Offspring phenotype: Females: rickets Males: healthy Marriage #2: Mother phenotype: Rickets Father phenotype: Healthy Offspring phenotype: Females: 50% rickets, 50% healthy Males: 50% rickets, 50% healthy Marriage #3: Mother phenotype: Rickets Father phenotype: Healthy Offspring phenotype: Females: rickets Males: rickets Marriage #4: Mother phenotype: Healthy Father phenotype: Healthy Offspring phenotype: Females: healthy Males: healthy Question: What is the inheritence mode of the disease? Note: In the question, there's no mention of the married couples being related to each other in any way, so I'm assuming these couples are not relatives. - My conclusion considering the given data is that the inhertence mode of the disease is autosmal recessive. If it were dominant (either autosomal or x-linked), the disease would've been somehow expressed in marriage #4. It doesn't seem to be x-linked recessive, looking at marriage #2. If it were X-linked recessive, for 50% of their offspring to be sick in marriage #2, the father would have to carry a recessive mutant gene as well. If he were carrying a recessive mutant gene, he would have been sick, yet he's healthy. For 50% of the offspring to be healthy (as showed), there would need to be a dominant gene preventing the mutant recessive gene from being expressed. I'm just trying to figure out whether my way of going about solving this question is correct or not...
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