Neurological complications associated with Down syndrome

Down Syndrome (DS) is a genetic disorder characterized by having one extra chromosome 21 and manifests in different neurologic complications that negatively impact people's lives. Seizures, epilepsy, intellectual disability, and early onset of cognitive impairment are among some of the manifestations associated with DS. In this review, a comprehensive examination of the neurologic abnormalities associated with DS will be provided, using a developmentally oriented approach. The neurodevelopmental disorders in individuals with DS will be outlined, especially those related to early life (intellectual disability and motor function). Late onset problems will also be discussed such as seizures and progressive dementia. Molecular bases responsible for causing neurological problems will be discussed, especially concerning the function of gene overexpression on chromosome 21 including amyloid precursor protein ( APP) and dual-specificity tyrosine phosphorylation-regulated kinase 1 A ( DYRK1A ) which have been strongly correlated with AD neurodegeneration. The purpose of this review is to highlight the significant neurological problems that have a connection with DS, from clinical manifestations down to the molecular bases involved in neurological disorders related to DS. • Individuals with Down syndrome exhibit age-dependent neurological complications ranging from developmental delay and epilepsy to early-onset dementia. • Overexpression of chromosome 21 genes, particularly APP and DYRK1A , drives accelerated neurodegeneration and markedly increases the risk of Alzheimer's disease. • Early recognition of cognitive, behavioural, and seizure phenotypes enables timely intervention and improves long-term neurological outcomes.