Tay-Sachs disease is caused by a mutant recessive allele (aa).A husband and wife (without the disease) wonder if they are at risk for having a child with Tay Sachs.The odds of having a child with Tay Sachs for them were low, but in fact their first child did have Tay Sachs.The couple wants to have another child. What is the probability of having a second child with Tay Sachs?Provide the probability as percentage

Name: Tay-Sachs disease is caused by a mutant recessive allele (aa).A husba
Uploaded: 2024-03-20T06:43:04.000Z
Channel: Bartleby
Description: Tay-Sachs disease is caused by a mutant recessive allele (aa).A husband and wife (without the disease) wonder if they are at risk for having a child with Tay Sachs.The odds of having a child with Tay Sachs for them were low, but in fact their first

Tay-Sachs disease is a rare genetic condition marked by the absence of the enzyme hexosaminidase A (Hex-A), resulting in the buildup of GM2 ganglioside in nerve cells. Symptoms, such as neurological decline, seizures, and developmental regression, typically emerge during infancy. The disorder is caused by a mutations in the HEXA gene, follows an autosomal recessive pattern. Unfortunately, there is no cure, and most individuals with the infantile form do not survive beyond early childhood. Carrier screening is available, particularly for at-risk ethnic populations. Presently, management involves supportive care, and ongoing research explores potential gene therapies and enzyme replacement approaches.Genetic Background:The parents are carriers (Aa), and their first child with Tay-Sachs is homozygous recessive (aa).Punnett Square:The possible genetic combinations for the couple's offspring are represented in a Punnett square:AaAAAAaaAaaa3. Possible Genotypes of Offspring:From the Punnett square, there are three possible genotypes for the second child: AA, Aa, and aa.4. Probability Calculation:The probability of having another child with Tay-Sachs (aa) is given by the chance of the parents both passing on the recessive allele (a).Probability of aa=41This is because there are four possible combinations (AA, Aa, Aa, aa), and only one of those combinations results in a child with Tay-Sachs.5. Percentage Calculation:To express the probability as a percentage, multiply by 100:Percentage=41×100=25%The probability of the couple having a second child with Tay-Sachs is 25%.