Causes of Down Syndrome

Human cells typically contain 23 sets of chromosomes. One chromosome in each pair originates from the father, and the other is from the mother itself.

This disorder results when unusual cell division including chromosome 21 happens. These cell division variations from the norm result in an additional incomplete or full chromosome 21. This additional hereditary material is in charge of the trademark highlights and formative issues of Down disorder. Any of three hereditary varieties can cause Down disorder:

• Trisomy 21. Around 95 percent of the time, Down disorder is brought about by trisomy 21 — the individual has three duplicates of chromosome 21, rather than the typical two duplicates, in all cells. This is brought about by strange cell division amid the improvement of the sperm cell or the egg cell.

• Mosaic Down syndrome . In this uncommon type of Down disorder, an individual has just a few cells with an additional duplicate of chromosome 21. This mosaic of typical and anomalous cells is brought about by irregular cell division after treatment.

• Translocation Down syndrome . Down disorder can likewise happen when a part of chromosome 21 ends up appended (translocated) onto another chromosome, previously or at origination. These kids have the typical two duplicates of chromosome 21, yet they likewise have extra hereditary material from chromosome 21 joined to another chromosome.

There are no known conduct or natural factors that reason Down disorder.

Is it acquired?

More often than not, Down disorder isn’t acquired. It’s brought about by a mix-up in cell division amid early advancement of the hatchling.

Translocation Down disorder can be passed from parent to youngster. Nonetheless, just around 3 to 4 percent of kids with Down disorder have translocation and just some of them acquired it from one of their folks.

At the point when adjusted translocations are acquired, the mother or father has some revamped hereditary material from chromosome 21 on another chromosome, yet no additional hereditary material. This implies the person in question has no signs or side effects of Down disorder, however can pass an uneven translocation on to youngsters, causing Down disorder in the kids.