What gene does Down Syndrome affect?
1 Answer
Down's syndrome is a genetic disorder caused by the presence of all or a part of third copy of chromosomes 21.
Explanation:
In patients with Down's syndrome an error occurs in the coming together of chromosome 21.
The most common error in chromosome replication is trisomy 21, where the new cell gets three copies of chromosome 21 instead of two.
Translocation describes a less common event where an extra piece of chromosome 21 gets attached to another chromosome, again delivering more genetic material to the new cell than needed.
In a rare form the person has only some cells with an extra copy of chromosome 21. The mosaic of normal and abnormal cells is caused by abnormal cell division after fertilisation.
It is typically associated with physical growth delays, characteristic facial features and mild to moderate intellectual disability. Down's syndrome is not an illness or disease to be prevented but instead, an unexplained error in replicating DNA, genes, and chromosomes at the earliest stage of embryo development. The extra chromosome occurs by chance. There is no cure for Down's syndrome.
