Jun 11, 2012 · The complete extra copy of chromosome 21 is in all of the person’s cells—or a complete trisomy. Almost all Down syndrome cases result from complete trisomy 21. 1,2,3

Nov 22, 2023 · Down syndrome is a set of cognitive and physical symptoms that result from having an extra chromosome 21 or an extra piece of that chromosome. It is the most common …

Jun 11, 2012 · A diagnosis of Down syndrome after birth is often based initially on physical signs of the syndrome. But because individuals with Down syndrome may not have these …

Jun 14, 2012 · People with Down syndrome are at a greater risk for a number of health problems and conditions than are people who do not have Down syndrome. Many of these associated …

Jun 9, 2025 · Down syndrome (i.e., trisomy 21) has been known since the late 1950’s. Chromosome 21 was sequenced back in 2000, leading to the identification of ~225 genes. No …

Jun 22, 2012 · Children with Down syndrome are at an increased risk for some health problems, but not all will have serious health problems.

Mar 15, 2013 · During Trisomy Awareness Month in March, the NICHD joins other agencies and organizations in raising awareness about trisomy conditions and the challenges they may pose …

The symptoms of Down syndrome vary from person to person, and people with Down syndrome may have different problems at different times of their lives.

Jun 14, 2012 · Turner syndrome occurs when part or all of an X chromosome is missing from most or all of the cells in a girl’s body.

Nov 22, 2023 · Down syndrome is the most frequent chromosomal cause of mild to moderate intellectual disability, and it occurs in all ethnic and economic groups. 2 Researchers know …