Question

Рецессивный ген СОН1 , расположенный в 8-й хромосоме, обуславливает предрасположение к развитию выступающих резцов. Пенетрантность признака равна 65%. Определите вероятность, что у ребенка разовьется аномалия зубов, если известно, что выступающие резцы были у матери ребенка и деда по отцовской линии

Answer 1

1/2*1/4*0,65=0,125*=0,08125
8,125% низкая

Answer 2

Understanding the Question

The question is asking for the probability that a child will develop a tooth anomaly if the child's mother and paternal grandfather both have protruding incisors. The question provides information about a recessive gene called SON1, which is located on the 8th chromosome and is associated with a predisposition to developing protruding incisors. The question also states that the penetrance of this trait is 65%.

Calculating the Probability

To calculate the probability, we need to consider the inheritance pattern of the recessive gene and the information provided about the mother and paternal grandfather.

1. Inheritance Pattern: The recessive gene SON1 is inherited in an autosomal recessive manner. This means that both copies of the gene (one from each parent) must be present for the trait to be expressed. If only one copy is present, the individual will be a carrier but will not show the trait.

2. Information Provided: - The mother has protruding incisors, which means she must have at least one copy of the recessive gene. - The paternal grandfather also has protruding incisors, which means he must have at least one copy of the recessive gene.

3. Probability Calculation: - Since the mother has protruding incisors, she must have at least one copy of the recessive gene. Let's assume she is a carrier (heterozygous) and has one copy of the recessive gene (SON1) and one copy of the normal gene (SON1'). - The probability of the mother passing on the recessive gene to her child is 50%. - The paternal grandfather also has protruding incisors, so he must have at least one copy of the recessive gene. Let's assume he is a carrier (heterozygous) and has one copy of the recessive gene (SON1) and one copy of the normal gene (SON1'). - The probability of the paternal grandfather passing on the recessive gene to his child (the father of the child) is also 50%. - Therefore, the probability of the child inheriting the recessive gene from both the mother and the paternal grandfather is 50% * 50% = 25%. - Since the penetrance of the trait is 65%, the probability that the child will develop the tooth anomaly is 25% * 65% = 16.25%.

Conclusion

Based on the information provided, the probability that the child will develop a tooth anomaly is approximately 16.25%.