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ilex24 07-02-2005 12:41 PM

Can any one give me some information about Mosiac down syndrome please?

My boyfriend's little girl has down syndrome, they now think it is Mosaic, and i'd like to know more about it.

Thank you


gardenandcats 07-03-2005 05:18 AM

Re: Mosaic
At the present time, there is not much research on the similarities and differences between simple trisomy 21 and mosaic trisomy 21. One report published in 1991 on mental development in Down syndrome mosaicism compared 30 children with mosaic Down syndrome with 30 children with typical Down syndrome. IQ testing showed that the mean IQ of the mosaic group was 12 points higher than the mean of the non-mosaic group. However, some children with typical Down syndrome did score higher on the IQ tests than some of the children with mosaic Down syndrome.
The Department of Human Genetics at the Medical College of Virginia has had an ongoing study project of children with mosaic DS. In a survey of 45 children with mosaicism, they found that these children did show delayed development compared to their siblings. When 28 of these children with mosaicism were matched up with 28 children with typical Down syndrome for age and gender, the children with mosaicism reached certain motor milestones earlier than children with typical DS, such as crawling and walking alone. However, the speech development was equally delayed in both groups.

hmahappy 09-06-2005 11:07 AM

Re: Mosaic
D.S. is also known as trisomy 21- because D.S.s have an extra chromosome- the "tri" in trisomy, as opposed to chromosomes being in pairs. so a DS has all chromosomes in pairs except for chrom#21 which is in triplets.

Most DS in the world are a result of this trisomy in the mother's ovum- like when she's old, or in the father's sperm, carried through families.

Mosaics are different because the ovum and sperm are NORMAL, but AFTER fertilization and when the baby starts to be formed, some of the cells for some spontaneous usually unknown reason get this 'mutation' and become trisomy, all of these cells when they continue to divide give trisomy cells. But the other cells not affected are still normal! that's why they are called MOSAIC- they have both normal and trisomy cell lines.

Mosaics are 1% of DS.

My sister is mosaic, and i often feel like i can see both cell lines- sometimes she's so incredibly normal, mature, smart, like she can remember everything and like she understands everything. And at the same time she's like a child that never grows up. Its hard to explain really. And she always felt she was normal- she never liked going to the 'disabled' schools. I think mosaics are usually smarter than other DS.

Though I'm sorry about your gf, but really, DS are a blessing, and angels to have around, I grew up with my sister and she's the best source of unconditional love i have, i feel lucky.
take care!

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