These include non-mosaic Down's syndrome as well as other congenital anomalies, chromosomal disorders, dysmorphic syndromes, metabilic disorders and perinatal infections diseases that affect multiple body systems.

People with non-mosaic Down's syndrome are considered to be disabled from birth. The level of disability caused other disorders in this category varies widely. Generally speaking, these disorders are evaluated by determining which other body systems are affected and determining the extent of disability caused by the resulting dysfunction of those systems.