0
Down syndrome is caused by a third copy on chromosome 21 and is present at conception or shortly after. It is mostly a random (and relatively common) occurrence, unless it is of the translocation type which is rare and genetic.
Wiki User
∙ 12y ago
Wiki User
∙ 14y agoDown syndrome is caused by an additional copy of chromosome 21. There is not a specific "gene" that causes it, the additional copy of the chromosome leads to other changes and processes that result in the condition. It is not dominant or recessive.
Wiki User
∙ 12y agoDown syndrome is not an allele. It is caused by a triplication of the 21st chromosome in the baby. Eggs and Sperm all have 1 copy of each chromosome so that the baby ends up with 46 chromosomes, 23 from mom and 23 from dad. Down syndrome happens when either the egg or sperm had 2 copies of the 21st chromosome, which when paired with the normal egg or sperm, there ends up being 3 copies of 21st.
Wiki User
∙ 13y agoDown syndrome is neither caused by dominant or recessive chromosomes it is simply caused by an error in the translation process of chromosome 21.
Wiki User
∙ 13y agoNo. down Syndrome is caused by a triplication (instead of a duplication) of the 21st Chromosome. It is not caused by an allele and is not inheritable in most cases.
Wiki User
∙ 8y agoPeople with Down's have a 50% chance of passing it on.
Add your answer:
Earn +20 pts
What can down syndrome be caused by?
Down's Syndrome is caused mainly by a mutation in the gene. It is a genetic disorder, which means it was passed on from parents to offspring.
Is Edward's syndrome caused by a recessive gene?
Edward's syndrome is not technically recessive or dominant, because it is not caused by a single gene. Rather it happens due to a trisomy of chromosome 18 (or just of a part of said chromosome). Parent's may be healthy and still have offspring with the syndrome not because its recessive, but because the trisomy arises during meiosis of the gametes. Whatever happens to the gametes affects only the offspring not the carrier parent.
Is down syndrome and pku caused by chromosomal abnormalities?
Down syndrome is caused by an additional chromosome while PKU is due to a mutation or defect in a gene.
Is Stickler Syndrome a dominant gene or a recessive gene?
Most commonly is caused by a mutation in one of three types of collagen genes - COL2A1, COL11A1, COL11A2 and is a dominantly inherited disease. A recessive type has also beed described with a mutation in the COL9A1 gene.
Is down's syndrome caused by a gene or chromosomal mutation?
Neither. It is an extra #21 chromosome.
Is cystic fibrosis caused by a dominent or recessive gene?
It is caused by a recessive allele. Believe me my teacher told me.
What is a good sentence for recessive gene?
A recessive gene is one that does not show outwardly unless the organism has two copies of it. If you have only one copy of a recessive gene, your appearance is that of the dominant gene. Here are some sentences.Red hair is caused by a recessive gene.The baby had two recessive genes for Tay-Sachs disease, and did not live.You cannot tell if someone has a recessive gene just by looking at them.
What causes zellweger syndrome?
Zellweger syndrome is caused by mutations in any one of at least 12 genes ; mutations in the PEX1 gene are the most common cause. It is inherited in an autosomal recessive manner. There is no cure for Zellweger syndrome; treatment is generally symptomatic and supportive.
What is a genetic disorder that a child can inherit from his parent?
The diseases sickle cell anemia and thalassemia, both of which are inherited blood disorders caused by recessive genes. The child must get the recessive gene from both of their parents to have the disease. If the child only gets the recessive gene from one parent, they will be a healthy carrier.
What is an example of a disordor caused by a recessive gene?
Type 1 diabetes
Is there a specific gene for down syndrome?
No.
What kind of mutation is triple x syndrome?
Most cases of triple X syndrome are not inherited so it is not a dominant or recessive trait.
