Journal of Down Syndrome & Chromosome Abnormalities
Open Access

Abstract

How does a 1.5-Fold Increase in Gene Dosage in Chromosome 21 Cause the Pleiotropic Phenotypes in Down Syndrome?

Baojin Ding

Down syndrome (DS) is caused by the presence of all or part of an extra copy of human chromosome 21 (HSA21) [1]. As many organs and systems are affected, DS patients show highly complex clinical features, such as distinctive facial morphology, intellectual disabilities, hypotonia, heart defects, as well as abnormalities of the gut and the immune system [2]