what are the chances of parents who are both heterozygous for sachs(Tt) having a child with Tay -Sachs disease?
2007-02-23 12:37:17 · 5 answers · asked by Sevket Serkan A 1 in Health ➔ Diseases & Conditions ➔ Other - Diseases
TSD is a recessive genetic disorder, meaning that both parents must be carriers in order to give birth to an affected child. Even then, there is only a 25% chance with each pregnancy of having a child with TSD. Prenatal monitoring of pregnancies is available.
An issue of debate is whether Tay-Sachs, the genetic disorder, may have once provided a heterozygote advantage in the Ashkenazi Jewish population. The disease is autosomal recessive. In its most common form, paralysis, dementia, blindness, and death occur within a few years after birth. Approximately one in every 27 Ashkenazi Jews is a carrier of Tay-Sachs, and the common Ashkenazi mutation is also prevalent among the Cajuns of southern Louisana. It occurs at a low rate in several other Jewish populations. An unrelated mutation, which produces the same pathology, is common among French Canadians.
In the general population, the incidence of carriers (heterozygotes) is about 1 in 300.
2007-02-23 12:46:11 · answer #1 · answered by ira a 4 · 0⤊ 0⤋
My nephew had this disease. I don't know if you know much about it but if both parents are carriers as my sister and her husband were then you have a great chance of a child being born with the disease. She had two children but only Joshua her oldest had the disease. Her youngest son is a carrier. Joshua was the only one in the United States living with this disease(he made the news and the newspapers) He was our miracle because he had infantile and should have passed at the age of 8 but we had him until he was 13. We did talk to a couple who had 13 children and they all had the disease. I don't understand why they kept having children. It used to be mandatory that you be checked when you get your blood work done before getting married to see if you were carriers...I think it still should be. Joshua died a terrible, painful death so if you know for sure that you are both carriers please consider what you would put a child through. No parent should have to watch their child die. If you would like more info. on this please e-mail me at Dooney_bug@hotmail.com. I am putting my personal e-mail on this page because this disease is that serious.
2007-02-23 16:23:46 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Usually in the busy World of Genetics, things kind of skip a generation. If you or your spouse, mainly your spouse is a carrier their is a 60% or greater risk that your grand kids (female) could inherit the decease.
Look back on your family History yours and hers as this is also a good indicator of genetics in action, however, if you two have the recipe for initiating this decease it could happen starting with your grand kids (90% risk) and (kids 10%), and if it does usually it is the female that has the carrier gene.
RD
2007-02-23 12:49:44 · answer #3 · answered by Richard D 3 · 0⤊ 0⤋
Seriously?
You've gotta be able to do something as simple as a single allele punnett square or you'll have no chance to pass freshman biology.
2007-02-23 12:40:25 · answer #4 · answered by Anonymous · 0⤊ 0⤋
1 in 4.
Or 1/4.
Or 25%.
Just make the Punnett square.
..............T..........t
........T...TT........Tt
........t.... Tt.........tt
(Sorry for the bad form. It's hard to make a Punnett square on this.)
2007-02-23 13:18:15 · answer #5 · answered by Alex 2 · 0⤊ 0⤋