03/25/2026
MARCH IS DEVELOPMENTAL DISABILITIES AWARENESS MONTH.
It might be helpful to think about Developmental Disabilities in terms of the body parts or systems they affect or how they occur. For example:
• Nervous system
These disorders affect how the brain, spinal cord, and nervous system function, which can affect intelligence and learning. These conditions can also cause other issues, such as behavioral disorders, speech or language difficulties, seizures, and trouble with movement. Cerebral palsy,5 Down syndrome, Fragile X syndrome, and autism spectrum disorders (ASDs) are examples of IDDs related to problems with the nervous system.
• Sensory system
These disorders affect the senses (sight, hearing, touch, taste, and smell) or how the brain processes or interprets information from the senses. Preterm infants and infants exposed to infections, such as cytomegalovirus, may have reduced function with their eyesight and/or hearing. In addition, being touched or held can be difficult for people with ASDs.
• Metabolism
These disorders affect how the body uses food and other materials for energy and growth. For example, how the body breaks down food during digestion is a metabolic process. Problems with these processes can upset the balance of materials available for the body to function properly. Too much of one thing, or too little of another can disrupt overall body and brain functions. Phenylketonuria (PKU) and congenital hypothyroidism are examples of metabolic conditions that can lead to IDDs.
• Degenerative
Individuals with degenerative disorders may seem or be typical at birth and may meet usual developmental milestones for a time, but then they experience disruptions in skills, abilities, and functions because of the condition. In some cases, the disorder may not be detected until the child is an adolescent or adult and starts to show symptoms or lose abilities. Some degenerative disorders result from other conditions, such as untreated problems of metabolism.