In the 1996 mosaic Down syndrome research publication of the Medical College of Virginia (MCV), Virginia Commonwealth University, researchers matched 28 pairs of individuals with mosaic and non-mosaic Down syndrome. This match was to compare the similarities and differences of mosaic and non-mosaic Down syndrome. With the exception of speech, there was a trend toward individuals with mosaic DS reaching the milestone evaluated at an earlier age than those with non-mosaic Down syndrome. However, a clear difference (identified by statistical testing) was apparent only for crawling and walking.
|Milestone||Mosaic Down syndrome||Non-Mosaic DS|
Spoke first word other than mama/dada
|Drank from cup alone|
|Walked up stairs|
* = statistical difference between mosaic and non-mosaic groups
IMDSA recognizes that this is an average age and in no way an absolute guideline for when individuals with mosaic Down syndrome will meet their milestones .
In another part of this study 45 individuals ranging in the age of 4 months to 33 yrs were compared to their siblings when asked when each group met developmental milestones.
**Spoke first word
|*Walked up stairs|
* = statistical difference between children with mosaicism and their siblings
** = first word other than mama or dada
* Age in chart is counted by months
^ - AVG = Average
IMDSA recognizes that there is a wide age range in developmental milestones for children with mosaic Down syndrome and in most cases, a significant developmental delay when compared to their siblings according to this research conducted by MCV.