Chromosome 21 is tripled in Down syndrome.
if you mean chromosome its the 15th......
It is the result of a chromosomal abnormality, in which there is an extra chromsome on the chromosome 21 pair. This is call trisomy 21.
Barth syndrome occurs when a person is born with a mutated, or abnormal, TAZ1 (or G4.5) gene. This abnormal gene is located on the X chromosome, which is a sex-determining chromosome. Males have one X and one Y chromosome, while females have two X chromosomes.
Lowe syndrome is caused by a mutated gene on the X sex chromosome. Because it is X-linked, it occurs almost exclusively in males.
Noonan syndrome is primarily caused by mutations in the PTPN11 gene, located on chromosome 12. This gene provides instructions for making a protein involved in cell signaling and development. Changes in this gene can disrupt normal cell signaling pathways and lead to the characteristic features of Noonan syndrome.
Rubinstein-Taybi syndrome is caused by a non-functional copy of the BREP binding protein gene (either by mutation or deletion) on chromosome 16.
Neither. It is an extra #21 chromosome.
Fragile X syndrome is caused by a mutation that prevents the Fragile X mental retardation (Fmr-1) gene from being transcribed. This gene is located on the X chromosome (the sex chromosome). Since males only carry one of these chromosomes, they are twice as likely to be affected by the mutation than females.
Down syndrome is caused by an additional chromosome while PKU is due to a mutation or defect in a gene.
Down syndrome is a result of having an extra chromosome in one's genes. Chromosome thirteen* if your that much into the science. It is also called trisomy 21 because the chromosome 21 is the one with the abnormalities. *Abnormalities with chromosome thirteen is called Patau syndrome or trisomy 13.
Chromosome mutations can result in changes in the number of chromosomes in a cell or changes in the structure of a chromosome. Unlike a gene mutation which alters a single gene or larger segment of DNA on a chromosome, chromosome mutations change and impact the entire chromosome.
The defective gene in Hurler syndrome is located on chromosome 4. This gene carries instructions for making an enzyme called alpha-L-iduronidase, which is essential for breaking down certain complex molecules in the body. When this gene is mutated, the enzyme is deficient, leading to the accumulation of harmful substances in the cells.