Types of Down Syndrome

Types of Down Syndrome

Down Syndrome has three types.

1. Trisomy 21 (nondisjunction)
2. Mosaicism

3. Translocation

Below is a chart outlining the process of normal cell division.

Trisomy 21 (Nondisjunction) (Down Syndrome Treatment)

Down Syndrome is ordinarily caused by an error in cell division called “nondisjunction.”
Nondisjunction results in an embryo with three of chromosome twenty-one instead of the usual two. Prior to or at conception, pairs of 21st chromosomes in either sperm or
the egg fails to separate.

As the embryo develops, the extra chromosome replicates in every cell of the body. In most cases this
type of Down syndrome Trisomy 21, counts for 95%.

Mosaicism

Mosaicism (or mosaic Down syndrome) exists when there is a mixture of two types of

cells, some are containing the usual 46 chromosomes and some containing forty-seven.

Those cells with forty-seven chromosomes contain an extra chromosome 21.

Mosaicism is the least usual form of Down syndrome. It accounts for only about one

per cent of all cases of Down syndrome. Research indicates that individuals with

mosaic down syndrome may have different features as compared to the other one. However, broad generalisations are

not possible due to the full range of abilities children with Down syndrome possess.

Translocation (Down Syndrome Treatment)

In translocation, which accounts for about four per cent of cases of Down syndrome,

the total number of chromosomes in the cells remains forty-six. However, an extra copy of chromosome 21 in whole or in part is connected to another chromosome, normally fourteen chromosomes. The presence of the extra full or partial chromosome

twenty one causes the characteristics of Down syndrome.

Can people with Down syndrome marry (Down Syndrome Treatment)

Many people with Down syndrome marry. Although there have rare exceptions,

most men with Down syndrome cannot become the father of a child. In any pregnancy, a woman
with Down syndrome has a 50/50 chance of conceiving a kid with Down syndrome,
although several of the pregnancies are miscarried.