What are the genetics of Trisomy 21? (autosomal, sex-linked, recessive, dominant, etc)??
Question: is it autosomal, sex-linked, recessive, dominant, etc? or is it non-disjunction. im confused about it all. .
Answers: What are the genetic changes related to Down syndrome?
Down syndrome is related to chromosome 21.
Most cases of Down syndrome result from trisomy 21, which means each cell in the body has three copies of chromosome 21 instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of Down syndrome. Although the connection between Down syndrome and Alzheimer disease is unclear, researchers believe that an extra copy of a particular gene on chromosome 21, the APP gene, may account for the increased risk.
A small percentage of Down syndrome cases occur when only some of the body's cells have an extra copy of chromosome 21. These cases are called mosaic Down syndrome.
Although uncommon, Down syndrome also can occur when part of chromosome 21 becomes attached (translocated) to another chromosome before or at conception. Affected people have two copies of chromosome 21, plus extra material from chromosome 21 attached to another chromosome. These cases are called translocation Down syndrome.
Can Down syndrome be inherited?
Most cases of Down syndrome are not inherited, but occur as random events during the formation of reproductive cells (eggs and sperm). An error in cell division called nondisjunction results in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 21. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 21 in each of the body’s cells.
Mosaic Down syndrome is also not inherited. It occurs as a random error during cell division early in fetal development. As a result, some of the body’s cells have the usual two copies of chromosome 21, and other cells have three copies of the chromosome.
Translocation Down syndrome can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 21 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 21. Although they do not have signs of Down syndrome, people who carry this type of balanced translocation are at an increased risk of having children with the condition.
Hope that may help you!
Good luck!
Answers: What are the genetic changes related to Down syndrome?
Down syndrome is related to chromosome 21.
Most cases of Down syndrome result from trisomy 21, which means each cell in the body has three copies of chromosome 21 instead of the usual two copies. The extra genetic material disrupts the normal course of development, causing the characteristic features of Down syndrome. Although the connection between Down syndrome and Alzheimer disease is unclear, researchers believe that an extra copy of a particular gene on chromosome 21, the APP gene, may account for the increased risk.
A small percentage of Down syndrome cases occur when only some of the body's cells have an extra copy of chromosome 21. These cases are called mosaic Down syndrome.
Although uncommon, Down syndrome also can occur when part of chromosome 21 becomes attached (translocated) to another chromosome before or at conception. Affected people have two copies of chromosome 21, plus extra material from chromosome 21 attached to another chromosome. These cases are called translocation Down syndrome.
Can Down syndrome be inherited?
Most cases of Down syndrome are not inherited, but occur as random events during the formation of reproductive cells (eggs and sperm). An error in cell division called nondisjunction results in reproductive cells with an abnormal number of chromosomes. For example, an egg or sperm cell may gain an extra copy of chromosome 21. If one of these atypical reproductive cells contributes to the genetic makeup of a child, the child will have an extra chromosome 21 in each of the body’s cells.
Mosaic Down syndrome is also not inherited. It occurs as a random error during cell division early in fetal development. As a result, some of the body’s cells have the usual two copies of chromosome 21, and other cells have three copies of the chromosome.
Translocation Down syndrome can be inherited. An unaffected person can carry a rearrangement of genetic material between chromosome 21 and another chromosome. This rearrangement is called a balanced translocation because there is no extra material from chromosome 21. Although they do not have signs of Down syndrome, people who carry this type of balanced translocation are at an increased risk of having children with the condition.
Hope that may help you!
Good luck!
More questions & answers:
- Recessive genetic disorder?
- What recessive X-linked disorder runs in the english royal family?
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- What is the difference between dominant and recessive?
- What determines whether an allele is dominant, recessive, or codominant?
- What is the difference between homozygous dominant, homozygous recessive, and heterozygous?
- Is the genetic Disease Polio Dominant or Recessive?
- Is Alzheimer's disease hereditory, and if so is it recessive or dominant?
- Is congenital ptosis of the eyelid a dominate trait or a recessive trait?
- Is Parkinsons disease passed down from a dominant or a recessive gene?
- Tay Sachs....?
Please do not quote my answers... it has been a while since AP Bio!! Recesive genetic disorders just mean that both parents have to be carriers of a disease for a child to have it!! If i am not mistak
It's believed to be porphyria - the malady that affected poor King George III - but nowadays they can test for it at birth and administer an appropriate medication to stop it developing.
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Still studying the genetic link to angelman's syndrome. From the research I have done, and who knows how much information on the internet is correct but I believe it is a sex-linked gene.
dominate traits can be expressed in the heterozygous gene state. This means if you have one dominant and one recessive gene the dominant will prevail. ie one blue and one brown, brown will prevail.
the genes of your parents.
Let
R= Dominant trait
r= Recessive trait
Homozygous dominant= RR
Homozygous recessive= rr
Heterozygous= Rr
Heterozygous individuals will have both traits, but its ph
R= Dominant trait
r= Recessive trait
Homozygous dominant= RR
Homozygous recessive= rr
Heterozygous= Rr
Heterozygous individuals will have both traits, but its ph
Polio is not genetic.
To date only dominant genes were linked to Alzheimer's, but there is new evidence, that a recessive gene, may play a role in the development of Alzheimer's.
If you have a family member with Alzhei
If you have a family member with Alzhei
Congenital ptosis may occur through autosomal dominant inheritance. Common familial occurrences suggest that genetic or chromosomal defects are likely.
Hi, I don't think anyone knows at this point in time. Currently the thought is that there is a genetic component with perhaps an environmental trigger. Do a search for Parkinson's there are probably h
I think it's recessive alleles. Both parents must be a carrier.
Infants with Tay-Sachs disease appear to develop normally for the first six months of life. Then, as nerve cells become distended wi
Infants with Tay-Sachs disease appear to develop normally for the first six months of life. Then, as nerve cells become distended wi