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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.
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Is lobster claw syndrome dominant or recessive?
Lobster claw syndrome, or Ectrodactyly, is a rare genetic condition caused by a mutation in the TP63 gene, which is inherited in an autosomal dominant pattern. This means that only one copy of the mutated gene is needed to display the syndrome.
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.
Iis down syndom caused by a dominant or recessive allele?
Down syndrome is caused by the presence of an extra copy of chromosome 21, known as trisomy 21. It is not caused by a single gene with a dominant or recessive inheritance pattern. It is a chromosomal disorder that can occur randomly during cell division.
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.
How do you get Morquio syndrome?
Morquio syndrome is a rare genetic disorder that is inherited in an autosomal recessive manner, meaning both parents must pass on a copy of the mutated gene for it to be expressed in the child. It is caused by a deficiency in enzymes involved in breaking down specific complex sugars, leading to the accumulation of these substances in cells and tissues.
Is waardenburg syndrome caused by a dominant or recessive allele?
Waardenburg syndrome is typically inherited in an autosomal dominant pattern, meaning that only one copy of the mutated gene is needed to develop the condition. However, there are rare cases where it can be inherited in an autosomal recessive pattern, requiring two copies of the mutated gene.
Is apert syndrome dominant or recessive?
Apert syndrome is typically caused by a sporadic mutation in the FGFR2 gene and is not inherited in a simple dominant or recessive manner. It is considered an autosomal dominant condition, with most cases arising from new mutations.
Is Stickler Syndrome a dominant gene or a recessive gene?
Stickler Syndrome is commonly inherited in an autosomal dominant pattern, meaning that a person only needs to inherit one copy of the mutated gene to develop the condition. However, in some cases, it can also be inherited in an autosomal recessive pattern.
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.
