Are there regional variations in the prevalence of Down syndrome?

Down syndrome is a genetic condition caused by extra copies of chromosome 21. It results in certain characteristics, including some degree of cognitive ... Nov 12, 2024 ... Down syndrome results from an unusual cell division involving chromosome 21. This unusual cell division results in an extra partial or full ... In 95% of cases there is the presence of an extra chromosome 21 in the cells, also lending the syndrome the name trisomy 21 (T21). The other causes are known as ... Apr 12, 1994 ... In addition, Dr. Lejeune was a pioneer in clinical cytogenetics and carried out numerous clinical and biochemical studies of people with Down ... Jan 25, 2025 ... Here are four factors that may be associated with an increased risk of having a baby with Down syndrome. Down syndrome is usually caused by an error in cell division called “nondisjunction.” Nondisjunction results in an embryo with three copies of chromosome 21 ... Down syndrome (sometimes called Down's syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome — hence its other name, ... Many children with Down's syndrome have some degree of hearing loss. Often this is caused by glue ear (a build-up of fluid in the middle ear) but there can be ... Jun 20, 2018 ... Down syndrome is a condition in which a person is born with an extra copy of chromosome 21. The condition is associated with intellectual disability. Oct 20, 2023 ... Down syndrome is a genetic disorder caused by an extra full or partial cell division of a human's chromosome 21, resulting in lifelong intellectual disability, ...