Overview
Monosomy 9q22.3 syndrome is a rare genetic condition caused by a missing piece of chromosome 9 in a region called 9q22.3. This deletion removes important genetic instructions that the body needs to develop normally. The condition is also sometimes called 9q22.3 microdeletion syndrome. Because this region contains a gene called PTCH1, many people with this syndrome share features with a condition called Gorlin syndrome (also known as Basal Cell Nevus Syndrome), including a higher risk of developing certain tumors. People with Monosomy 9q22.3 syndrome often have intellectual disability, delayed speech and language development, and behavioral challenges. Many also have distinctive facial features, problems with muscle tone, and seizures. Some individuals develop non-cancerous brain tumors called medulloblastomas or jaw cysts called keratocystic odontogenic tumors. Heart defects and skeletal abnormalities have also been reported in some cases. There is currently no cure for this condition. Treatment focuses on managing individual symptoms and may include special education support, speech and physical therapy, seizure medications, and regular monitoring for tumor development. Early intervention and a team of specialists can make a meaningful difference in quality of life for affected individuals and their families.
Also known as:
Key symptoms:
Intellectual disability or learning difficultiesDelayed speech and language developmentLow muscle tone (floppiness) in infancySeizures or epilepsyDistinctive facial features such as a broad forehead or widely spaced eyesBehavioral challenges including attention difficulties or autism-like featuresJaw cysts (keratocystic odontogenic tumors)Increased risk of brain tumors (medulloblastoma)Increased risk of basal cell skin cancersSkeletal abnormalities such as extra ribs or spine curvatureHeart defects present at birthShort statureCalcification of a brain structure called the falx cerebri
Clinical phenotype terms (46)— hover any for plain English
Variable
Can be inherited in different ways depending on the underlying gene
Neonatal
Begins at or shortly after birth (first 4 weeks)
Treatments
No FDA-approved treatments are currently listed for Monosomy 9q22.3 syndrome.
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Specialists
View all specialists →No specialists are currently listed for Monosomy 9q22.3 syndrome.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Monosomy 9q22.3 syndrome.
Community
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Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.What is the exact size of my child's deletion, and which genes are missing?,How often should my child be screened for jaw cysts, brain tumors, and skin cancers?,What therapies — speech, physical, or occupational — should we start right away?,Should other family members be tested for this deletion?,Are there clinical trials or research studies we should know about?,What signs should prompt us to seek emergency care?,What educational supports and services should we request for my child?
Common questions about Monosomy 9q22.3 syndrome
What is Monosomy 9q22.3 syndrome?
Monosomy 9q22.3 syndrome is a rare genetic condition caused by a missing piece of chromosome 9 in a region called 9q22.3. This deletion removes important genetic instructions that the body needs to develop normally. The condition is also sometimes called 9q22.3 microdeletion syndrome. Because this region contains a gene called PTCH1, many people with this syndrome share features with a condition called Gorlin syndrome (also known as Basal Cell Nevus Syndrome), including a higher risk of developing certain tumors. People with Monosomy 9q22.3 syndrome often have intellectual disability, delayed
At what age does Monosomy 9q22.3 syndrome typically begin?
Typical onset of Monosomy 9q22.3 syndrome is neonatal. Age of onset can vary across affected individuals.