9q31 1q31 3 Microdeletion Syndrome C4750910
A rare genetic condition from missing genetic material in a specific region of chromosome 9. May affect development, growth, and cause various medical concerns. Treatment focuses on symptom management and supportive therapies.
Key facts at a glance
- ICD-10
- Q89.9
- ICD-11
- LA00.0
- Body system
- congenital
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Congenital heart defects
Structural heart abnormalities such as ventricular septal defects, atrial septal defects, or other cardiac malformations.
Cardiac evaluation with echocardiogram is essential; seek immediate care if symptoms of heart failure develop such as rapid breathing, poor feeding, or bluish discoloration.
Kidney and urinary tract abnormalities
Structural anomalies of the kidneys or urinary tract including hydronephrosis, renal cysts, or duplicated collecting system.
Renal ultrasound recommended at diagnosis; seek urgent care for urinary retention, infection symptoms, or flank pain.
Seizures
Epileptic episodes that may vary in type from focal to generalized seizures.
Any seizure activity requires urgent neurological evaluation; seek emergency care for prolonged or repeated seizures.
Global developmental delay
(constitutional)Significant delays in reaching developmental milestones such as sitting, walking, and speaking compared to typical peers.
Frequency: 90-100% of patients
Intellectual disability
(neurologic)Range from mild to moderate cognitive impairment affecting learning, problem-solving, and adaptive functioning.
Frequency: 85-95% of patients
Prenatal and postnatal growth retardation
(constitutional)Slow growth both during pregnancy and after birth, resulting in short stature compared to age-matched peers.
Frequency: 70-80% of patients
Distinctive facial features
(dysmorphic)May include abnormal head shape, distinctive eyebrows, nose anomalies, ear abnormalities, and jaw underdevelopment.
Frequency: 60-75% of patients
Feeding difficulties
(gastrointestinal)Infants may have trouble with feeding, including poor suck, reflux, and difficulty transitioning to solid foods.
Frequency: 50-65% of patients
Hypotonia
(musculoskeletal)Reduced muscle tone resulting in floppy infant appearance and delayed motor skills such as head control and sitting.
Frequency: 55-70% of patients
Autistic spectrum behaviors
(behavioral)Features consistent with autism spectrum disorder including social communication difficulties, repetitive behaviors, and sensory sensitivities.
Frequency: 20-35% of patients
Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Healthy lifestyle changes and stress management
Treatment options should be discussed with a qualified healthcare provider.
Multisystem Surveillance Protocol
Regular monitoring for renal abnormalities, skeletal anomalies, and developmental delays characteristic of this chromosomal region deletion.
Gross Motor Development Program
Targeted physical therapy addressing hypotonia, joint laxity, and coordination challenges commonly seen in this syndrome.
Additional treatment options
Orthopedic Intervention Planning
Surgical evaluation for skeletal manifestations including limb abnormalities, scoliosis, or foot deformities that may require corrective procedures.
surgicalEducational Support Services
Individualized education planning with learning support, speech therapy coordination, and behavioral interventions.
psychologicalAdaptive Lifestyle Modifications
Environmental adaptations, assistive devices, and activity modifications to maximize independence and safety.
lifestyleWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is 9q31 1q31 3 Microdeletion Syndrome C4750910?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Luo Y, Zhao J, Wu J, et al. Clinical and genetic characterization of 9q31-q33 microdeletion syndrome: a case report and literature review. Molecular Cytogenetics. 2021;14(1):42.
Mandel H, Shotelersuk V. 9q34 Microdeletion Syndrome (Kleefstra Syndrome). GeneReviews. 2020.
McKusick VA. Mendelian Inheritance in Man. 12th ed. Johns Hopkins University Press; 1998. 9q deletion syndromes.
Wat MJ, Shchelochkov OA, Holder AM, et al. Chromosome 9q31.1-q31.3 microdeletion: a novel chromosomal abnormality and case report. American Journal of Medical Genetics Part A. 2009;149A(12):2698-2704.
OMIM #610335: 9q31.1q31.3 Microdeletion Syndrome. Online Mendelian Inheritance in Man.
Coe BP, Witherspoon K, Rosenfeld JA, et al. Refining analyses of copy number variation identifies specific genes associated with developmental delay. Nature Genetics. 2014;46(10):1063-1071.
Miller DT, Adam MP, Aradhya S, et al. Consensus statement: chromosomal microarray is a first-tier clinical diagnostic test for individuals with developmental disabilities or congenital anomalies. American Journal of Human Genetics. 2010;86(5):749-764.
American College of Medical Genetics and Genomics. Clinical Genetics: A Guide to Genetic Testing and Counseling. ACMG Guidelines. 2020.
Kleefstra T, de Brouwer AF, Crolla JA, et al. Cryptic chromosome 9q34 deletion results in RUNX1B haploinsufficiency. European Journal of Medical Genetics. 2009;52(5):279-283.
Rosenfeld JA, Coe BP, Eichler EE, Cotsapas C, Kahn RA. Estimates of penetrance for pathogenic CNVs. Nature Genetics. 2013;45(6):698-699.
Medication Comparisons
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This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy