Question

У здоровых родителей родился глухонемой ребенок, заболевший фенилкетонурией. Известно, что у супругов бабушки страдали фенилкетонурией, а дедушки были глухонемыми. Какова вероятность рождения следующего ребенка здоровым? Страдающим только одним заболеванием?

Answer 1

Я думаю ,что 25%. Так как 75-норма,а 25%-болезнь

Answer 2

Probability of the Next Child Being Healthy

The probability of the next child being healthy can be determined by considering the inheritance patterns of the conditions in question. In this case, we have two conditions: phenylketonuria (PKU) and deafness. Let's break down the probabilities for each condition separately.

Phenylketonuria (PKU): PKU is an autosomal recessive disorder, which means that both parents must be carriers of the PKU gene in order for their child to be affected. If both parents are carriers, there is a 25% chance that their child will have PKU, a 50% chance that the child will be a carrier like the parents, and a 25% chance that the child will neither have PKU nor be a carrier.

In this case, we know that the grandparents on both sides of the family had PKU. This means that both parents are carriers of the PKU gene. Therefore, there is a 25% chance that the next child will have PKU, a 50% chance that the child will be a carrier, and a 25% chance that the child will neither have PKU nor be a carrier.

Deafness: Deafness can have various causes, including genetic factors. In this case, we know that both grandfathers were deaf. However, we don't have information about the parents' hearing status. Therefore, it is difficult to determine the exact probability of the next child being deaf.

However, if we assume that the deafness in the grandfathers was due to a genetic cause, we can consider the possibility of an autosomal recessive inheritance pattern. If both parents are carriers of a deafness-causing gene, there is a 25% chance that their child will be deaf, a 50% chance that the child will be a carrier, and a 25% chance that the child will neither be deaf nor be a carrier.

Overall Probability: Since the two conditions, PKU and deafness, are independent of each other, we can multiply the probabilities of each condition to determine the overall probability of the next child being healthy or having only one of the conditions.

If we assume that both parents are carriers of both conditions, the probability of the next child being healthy (not having PKU and not being deaf) is calculated as follows:

0.75 (probability of not having PKU) * 0.75 (probability of not being deaf) = 0.5625, or 56.25%.

Similarly, the probability of the next child having only one of the conditions (either PKU or deafness) can be calculated as follows:

0.25 (probability of having PKU) * 0.75 (probability of not being deaf) + 0.75 (probability of not having PKU) * 0.25 (probability of being deaf) = 0.375, or 37.5%.

Please note that these probabilities are based on the assumption that both parents are carriers of both conditions. If the parents are not carriers of both conditions, the probabilities may be different.