Overview
Homozygous 2p21 microdeletion syndrome is an extremely rare genetic condition caused by the loss of a small piece of genetic material on both copies of chromosome 2, in a region called 2p21. This syndrome is also sometimes referred to as the SLC3A1/PREPL contiguous gene deletion syndrome. Because this deletion removes several genes at once, the condition affects multiple body systems. The key features of this syndrome include cystinuria (a condition where the amino acid cystine builds up in the urine, leading to kidney stones), neonatal or infantile hypotonia (low muscle tone from birth or early infancy), failure to thrive, feeding difficulties, and growth hormone deficiency. Some children may also experience developmental delays and intellectual challenges. The kidney stones from cystinuria can cause significant pain and urinary tract problems if not managed. Treatment is mainly supportive and symptom-based. Kidney stones from cystinuria are managed with high fluid intake, dietary changes, and sometimes medications to reduce cystine levels in the urine. Growth hormone therapy may be used for growth hormone deficiency. Physical therapy and occupational therapy can help with low muscle tone and developmental delays. There is currently no cure that addresses the underlying genetic cause, so lifelong monitoring and management by a team of specialists is important.
Also known as:
Key symptoms:
Low muscle tone from birth (floppy baby)Feeding difficulties in infancyFailure to thrive or poor weight gainKidney stones (from cystinuria)Blood or pain in the urineGrowth hormone deficiencyShort statureDevelopmental delaysIntellectual disability (variable severity)Droopy eyelids (ptosis)Muscle weaknessDelayed motor milestones such as sitting and walking
Autosomal recessive
Passed on when both parents carry the same gene change; often skips generations
Neonatal
Begins at or shortly after birth (first 4 weeks)
FDA & Trial Timeline
1 eventUniversitaire Ziekenhuizen KU Leuven — NA
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Homozygous 2p21 microdeletion syndrome.
1 clinical trialare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Specialists
View all specialists →No specialists are currently listed for Homozygous 2p21 microdeletion 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 Homozygous 2p21 microdeletion 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.How severe is my child's deletion and which genes are affected?,What is the best plan to prevent kidney stones from cystinuria?,Does my child need growth hormone therapy, and when should it start?,What therapies (physical, occupational, speech) does my child need right now?,How often should my child have kidney and urine monitoring?,Are there any clinical trials or new treatments being studied for this condition?,What is the chance that our future children could have the same condition?
Common questions about Homozygous 2p21 microdeletion syndrome
What is Homozygous 2p21 microdeletion syndrome?
Homozygous 2p21 microdeletion syndrome is an extremely rare genetic condition caused by the loss of a small piece of genetic material on both copies of chromosome 2, in a region called 2p21. This syndrome is also sometimes referred to as the SLC3A1/PREPL contiguous gene deletion syndrome. Because this deletion removes several genes at once, the condition affects multiple body systems. The key features of this syndrome include cystinuria (a condition where the amino acid cystine builds up in the urine, leading to kidney stones), neonatal or infantile hypotonia (low muscle tone from birth or ea
How is Homozygous 2p21 microdeletion syndrome inherited?
Homozygous 2p21 microdeletion syndrome follows a autosomal recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Homozygous 2p21 microdeletion syndrome typically begin?
Typical onset of Homozygous 2p21 microdeletion syndrome is neonatal. Age of onset can vary across affected individuals.
Are there clinical trials for Homozygous 2p21 microdeletion syndrome?
Yes — 1 recruiting clinical trial is currently listed for Homozygous 2p21 microdeletion syndrome on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.