Several disorders involve having 47 chromosomes instead of the usual 46. These disorders are types of trisomy, which means there is an extra copy of a chromosome.
Common Trisomy Disorders
According to the provided reference, the most common trisomy disorders are:
- Down syndrome
- Edward syndrome
- Patau syndrome
These conditions each arise from a different extra chromosome, leading to distinct characteristics.
Understanding Trisomy
In a typical human cell, there are 23 pairs of chromosomes, totaling 46. In trisomy, there's an extra copy of one of these chromosomes, meaning there are three copies of it, leading to 47 chromosomes total.
Details of the Common Trisomy Disorders
Here's a brief overview of each disorder:
| Disorder | Extra Chromosome | Common Characteristics |
|---|---|---|
| Down syndrome | Chromosome 21 | Intellectual disability, distinctive facial features, heart defects. |
| Edward syndrome | Chromosome 18 | Severe intellectual disability, heart defects, characteristic hand and foot deformities, low survival rate. |
| Patau syndrome | Chromosome 13 | Severe intellectual disability, heart defects, cleft lip and palate, low survival rate. |
Conclusion
A person with a trisomy, such as Down syndrome, Edward syndrome, or Patau syndrome has 47 chromosomes.
