The most common live-born human aneuploidy is trisomy 21, which causes Down syndrome (DS). Dosage imbalance of genes on chromosome 21 (Hsa21) affects complex gene-regulatory interactions and alters development to produce a wide range of phenotypes, including characteristic facial dysmorphology.
Can a person with Down syndrome look normal?
People with Down syndrome all look the same. There are certain physical characteristics that can occur. People with Down syndrome can have all of them or none. A person with Down syndrome will always look more like his or her close family than someone else with the condition.
At what age does a child with Down syndrome talk?
Typically, these children have a much harder time learning to talk (expressive language) than with understanding what they hear (receptive language). On average, children with Down syndrome start using words around 16 months of age—about 6 months later than other children.
Do Down syndrome babies cry differently?
Just like any baby, infants who have Down syndrome will sometimes be fussy. The temperament of a baby with Down syndrome is not usually any different from the temperament of any other baby.