Galactosemia is inherited as an autosomal recessive trait. The successes of modern medicine make it possible

Galactosemia is inherited as an autosomal recessive trait. The successes of modern medicine make it possible to prevent the development of the disease and avoid the consequences of metabolic disorders. What is the probability of having sick children in a family where one of the spouses is homozygous for the galactosemia gene, but the development of the disease was prevented by his diet, and the second of the spouses is healthy and comes from a family that is well-off for this pathology?

Let us designate the gene that causes the disease with galactosemia by the letter “a”, the corresponding dominant gene will be designated as “A”.

According to the condition of the problem, one of the spouses has compensated galactosemia – aa, because homozygosity is a condition under which a recessive trait acquires the ability to be realized in a phenotype. It produces a – type germ cells.

The second spouse is healthy and comes from a family that is free from galactosemia; his genotype will most likely look like this: AA. His body produces the same type of sex cells – A.

For this pair, the following offspring options are possible:

healthy children (Aa) – 100%;

Answer: the probability of having healthy children for this couple is 0%.