What are intellectual and developmental disabilities (IDDs)?

Intellectual and Developmental Disabilities (IDDs) are a group of disorders that affect cognitive function and physical or neurological development. These conditions can impact how people learn, communicate, and perform everyday activities. People with IDDs may struggle with communication, social interactions, self-care (like dressing, eating, and hygiene), problem-solving, and following rules or routines. People may have challenges in a few or all of these areas and may not be able to live alone without support.

What characteristics and symptoms do IDDs have?

IDDs include commonly known conditions such as autism spectrum disorder (ASD) and cerebral palsy. IDDs also encompass a range of rare genetic syndromes. Symptoms vary depending on the condition, the cause, and how severe the condition is. The most common signs include:

  • Delayed speech and language development
  • Difficulty with problem-solving and abstract thinking
  • Trouble with motor skills and coordination
  • Social and behavioral difficulties
  • Learning disabilities and academic struggles
  • Delayed or abnormal emotional development

Many IDDs are diagnosed in early childhood. However, some symptoms may become more noticeable as a person ages. People not diagnosed as children may struggle with daily living, social skills, or employment later in life.

Are genetic causes common for IDDs?

Research suggests that a significant portion of IDDs have a genetic basis. Studies estimate that up to 40% of people with IDDs have an identifiable genetic cause. These can include chromosomal abnormalities (e.g., Down syndrome), single-gene mutations (e.g., Fragile X syndrome), or copy number variations (CNVs). Advances in genetic technology have made it easier to find these variations and learn the root causes of IDDs.

How can genetic testing help people with IDDs?

Today, methods like whole-exome sequencing (WES) offer more comprehensive insights than previous types of genetic tests. At the same time, genetic testing is more affordable than ever before. A genetic diagnosis can help doctors, patients, and families better understand and manage conditions. Below are a few of the tangible benefits of genetic testing for people with IDDs.

Immediate Management: Knowing the genetic basis of a disorder opens the door to personalized, targeted care. Doctors can prescribe medication and other therapies to match the patient’s diagnosis and unique DNA.

Preventive Care: When the disorder and its cause are known, doctors have a better idea of what to watch for over time. This monitoring can catch potential problems before they get worse. Doctors can also teach patients and families how to reduce risk and symptoms.

Family Testing and Planning: Parents can learn the chances of passing on a genetic condition to children. Genetic counselors can also help you decide if other family members should be tested.

Support Networks: A confirmed diagnosis can link families to support groups, specialists, and resources. It may also help with qualifying for disability income and services.

Research and Clinical Trials: People with a genetic diagnosis may be able to participate in clinical research. This research can include drugs and therapies that could improve their lives.

Genetic testing for children with IDDs

Testing rates for children with IDDs have increased in recent years. Many pediatricians and specialists turn to genetic testing when a child has unexplained developmental delays, autism features, or intellectual disabilities. Still, access to and awareness of testing varies across the country.

Genetic testing for adults with IDDs

Today, many adults diagnosed with IDDs as children have never had genetic testing. The technology was not as advanced, and genetic causes were less understood. As a result, many adults with IDDs lack a precise diagnosis. In other cases, adults were not diagnosed with an IDD until they were older. Either way, there are several barriers to getting tested as an adult.

  • Limited Awareness: Many care providers and families don’t realize how helpful genetic testing can be for adults.
  • Insurance and Cost Issues: Insurance may be less likely to cover genetic testing for adults than kids.
  • Lack of Specialists: Clinics that do genetic counseling and testing for adults can be hard to find. Specialists are rare outside of large cities and university hospital systems.

Looking forward: Increasing the use of genetics

Genetic testing is crucial in understanding and managing Intellectual and Developmental Disabilities. While pediatric patients increasingly benefit from testing, many adults could still gain valuable insights from genetic evaluations. In an ideal world, genetic testing would be standard for both children and adults with IDDs. Expanding access to genetic testing can provide answers and improve the care and quality of life for people with IDDs and their families. 

At SequenceMD, many of our pediatric and adult patients come in as IDD referrals from their doctors. Through genetic evaluations, our care team of clinical geneticists, genetic counselors, and physician assistants helps patients get valuable insights into their health. These evaluations open the door to specialized care, personalized medication recommendations, connections to social services, risk reduction strategies, and more. To talk to SequenceMD about seeking a genetic evaluation, contact us today.