National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Chromosome 3q29 microduplication syndrome


Other Names:
Trisomy 3q29; Microduplication 3q29 syndrome
Categories:
This disease is grouped under:
Chromosome 3q29 microduplication syndrome is a rare chromosome abnormality characterized by having an extra copy of material (duplication) on a specific part of the long arm of chromosome 3. The signs and symptoms vary among affected individuals, but the most common features include mild or moderate intellectual disability and microcephaly. The condition may occur for the first time in the affected individual (de novo) or it can be inherited from a mildly affected or apparently normal parent.[1] Treatment is directed toward the specific signs and symptoms present in each individual.
Last updated: 5/30/2012
The signs and symptoms of chromosome 3q29 microduplication syndrome appear to vary among affected individuals. This condition has reduced penetrance, which means that some individuals with this chromosome abnormality do not have any signs and symptoms and are clinically unaffected.[2] Developmental delay, abnormally small head size (microcephaly) and ophthalmologic (eye-related) findings seem to be the most common features.[1][2] Other signs and symptoms that have been reported in affected individuals include cardiac (heart) abnormalities; poor muscle tone (hypotonia); speech delay; craniosynostosis; high palate (roof of the mouth); dental abnormalities; conductive hearing loss (hearing loss due to mechanical problems in the outer or middle ear); musculoskeletal abnormalities; and seizures.[2]
Last updated: 6/1/2012

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
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HPO ID
30%-79% of people have these symptoms
Abnormality of the dentition
Abnormal dentition
Abnormal teeth
Dental abnormality
[ more ] 		0000164
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
Global developmental delay 0001263
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ] 		0000252
Muscular hypotonia
Low or weak muscle tone
0001252
Obesity
Having too much body fat
0001513
5%-29% of people have these symptoms
Aniridia
Absent iris
0000526
Biparietal narrowing 0004422
Camptodactyly of toe 0001836
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
Cleft palate
Cleft roof of mouth
0000175
Craniosynostosis 0001363
Deep philtrum 0002002
Ectopic anus
Abnormal anus position
0004397
Hearing impairment
Deafness
Hearing defect
[ more ] 		0000365
High forehead 0000348
High palate
Elevated palate
Increased palatal height
[ more ] 		0000218
Iris coloboma
Cat eye
0000612
Large fontanelles
Wide fontanelles
0000239
Low-set ears
Low set ears
Lowset ears
[ more ] 		0000369
Macrocephaly
Increased size of skull
Large head circumference
Large head
[ more ] 		0000256
Microphthalmia
Abnormally small eyeball
0000568
Sandal gap
Gap between 1st and 2nd toes
Gap between first and second toe
Increased space between first and second toes
Sandal gap between first and second toes
Wide space between 1st, 2nd toes
Wide space between first and second toes
Wide-spaced big toe
Widely spaced 1st-2nd toes
Widely spaced first and second toes
Widened gap 1st-2nd toes
Widened gap first and second toe
[ more ] 		0001852
Sclerocornea
Hardening of skin and connective tissue
0000647
Seizure 0001250
Short neck
Decreased length of neck
0000470
Toe syndactyly
Fused toes
Webbed toes
[ more ] 		0001770
Ventricular septal defect
Hole in heart wall separating two lower heart chambers
0001629
Wide nasal bridge
Broad nasal bridge
Broad nasal root
Broadened nasal bridge
Increased breadth of bridge of nose
Increased breadth of nasal bridge
Increased width of bridge of nose
Increased width of nasal bridge
Nasal bridge broad
Wide bridge of nose
Widened nasal bridge
[ more ] 		0000431
1%-4% of people have these symptoms
Blepharophimosis
Narrow opening between the eyelids
0000581
Bulbous nose 0000414
Long face
Elongation of face
Increased height of face
Increased length of face
Vertical elongation of face
Vertical enlargement of face
Vertical overgrowth of face
[ more ] 		0000276
Low posterior hairline
Low hairline at back of neck
0002162
Multiple palmar creases
Multiple palm lines
0006114
Pes planus
Flat feet
Flat foot
[ more ] 		0001763
Round face
Circular face
Round facial appearance
Round facial shape
[ more ] 		0000311
Short nose
Decreased length of nose
Shortened nose
[ more ] 		0003196
Percent of people who have these symptoms is not available through HPO
Abnormally large globe
Increased size of eyes
Large eyes
[ more ] 		0001090
Autosomal dominant inheritance 0000006
Short palpebral fissure
Short opening between the eyelids
0012745
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Last updated: 7/1/2020
The prognosis for chromosome 3q29 microduplication syndrome varies depending on the presence and severity of signs and symptoms in each affected individual. Because microduplications have only more recently been diagnosed due to improving technology, it is not known with certainty what the long term affects are. Those who have no birth defects and are generally healthy likely will have a normal life expectancy, while individuals who are more severely affected may experience various complications.[3]
Last updated: 6/1/2012

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Chromosome 3q29 microduplication syndrome. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • My son was recently diagnosed with this disorder. His whole life he has been sick with ear infections, sinus infections and/or pneumonia. He is only 17 years old and has had pneumonia 8 times. In March they did blood work that indicated low levels in his immunoglobulin. Is having immune problems a characteristic of this condition? See answer

  • I just found out my granddaughter has this. I would like information on what exactly this is, and what happens with this condition. See answer


  1. Nicole MORICHON-DELVALLEZ. 3q29 microduplication. Orphanet. March 2011; http://www.orpha.net/consor/cgi-bin/Disease_Search.php?lng=EN&data_id=19607. Accessed 5/30/2012.
  2. Goobie S et al. Molecular and clinical characterization of de novo and familial cases with microduplication 3q29: guidelines for copy number variation case reporting. Cytogenet Genome Res. 2008;
  3. 3q29 duplications and microduplications. Unique. 2011; http://www.rarechromo.org/information/Chromosome%20%203/3q29%20Duplications%20and%20Microduplications%20FTNW.pdf. Accessed 6/1/2012.