Lurie Children’s Trisomy 9 Mosaic Syndrome (T9M) Program is the first clinic in the world dedicated to the care and research of individuals with T9M, a rare genetic condition. 

What is T9M?

Our genetic instructions are made of DNA, which is packaged into structures called chromosomes. Most individuals have 46 chromosomes which are arranged in 23 pairs. Having an extra chromosome is called a trisomy. Individuals with T9M have some cells (basic building blocks of our body) that have an extra copy of the 9th chromosome, leading to three chromosomes 9 in those cells instead of the usual two. The term "mosaic" means this extra chromosome is only present in some cells, not all. Having an extra copy of chromosome 9, even in a portion of the body, can lead to a range of health problems including developmental delay, growth issues, and different types of birth defects.  

The T9M Program aims to evaluate and support individuals with T9M and provide opportunities to participate in available research if families are interested. 

Why Choose Lurie Children's?

The genetic specialists in this clinic, Mindy Li, MD, and genetic counselor Kelsey Hogan, MS, CGC, both have experience with neurodevelopmental disorders and T9M. Dr. Li is the primary author of a publication on individuals with T9M that includes suggested clinical screening guidelines for this disorder. Our team is dedicated to supporting and advocating for both the physical and emotional needs of children and their families. 

Our Specialists

Mindy H. Li, MD

Attending Physician, Genetics, Genomics and Metabolism

Kelsey Hogan, MS, CGC

Genetic Counselor II, Genetics, Genomics and Metabolism

What to Expect

First Clinic Visit 

At the appointment, you will meet our T9M team, which includes a geneticist (doctor), Dr. Mindy Li and genetic counselor, Kelsey Hogan, MS, CGC. There may be additional team members present, such as medical trainees. We will review your child’s medical, surgical and family history, including prenatal (before birth), birth and developmental information. A child’s developmental history gives us information about their key growth milestones.

The visit will also include a physical exam. Our team can review and explain your child’s genetic test results as well. If you have copies of your child’s genetic test results available, it would be helpful to bring these to the visit. Our team will explain what next steps are recommended, such as medical imaging or baseline screenings,  if not completed already. We can also provide referrals to other specialists as needed. 

Follow-up Visits 

After the first visit, we may recommend regular follow-up with our team. This will vary depending on each family's needs but may be as frequently as annual visits. However, if any concerns arise between visits, our team is always available to help the children and families in our care. 

Make an Appointment

To schedule a first-time or return appointment, please call the Division of Genetics directly. This clinic occurs in person, but patients who live in Illinois may also request a telemedicine visit.  

Our Location

Ann & Robert H. Lurie Children's Hospital of Chicago

225 E. Chicago Ave.
Chicago, Illinois 60611

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Resources & Support


Our team has research projects related to T9M, including a natural history study to learn about the growth, development, and other medical findings of individuals with T9M of all ages. Although there is currently no treatment for T9M, we hope by learning as much as we can about T9M, we can improve the overall health care for these individuals.  

Related Specialties


For more information about the clinic, please call and request to connect with our clinic coordinator Kelsey Hogan.