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

17q23.1q23.2 microdeletion syndrome



Other Names:
17q23.1-q23.2 microdeletion syndrome; Del(17)(q23.1q23.2); Monosomy 17q23.1-q23.2; 17q23.1-q23.2 microdeletion syndrome; Del(17)(q23.1q23.2); Monosomy 17q23.1-q23.2; Monosomy 17q23.1q23.2; Chromosome 17q23.1-q23.2 deletion syndrome See More
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17q23.1q23.2 microdeletion syndrome is a condition caused by a small deletion of genetic material from chromosome 17. The deletion occurs at a location encompassing bands 23.1 to 23.2 on the long (q) arm of the chromosome. People with 17q23.1q23.2 microdeletion syndrome may have developmental delay, microcephaly, short stature, heart defects and limb abnormalities. Most cases are approximately 2.2 Mb in size and include the transcription factor genes TBX2 and TBX4 which have been implicated in a number of developmental pathways, including those of the heart and limbs.[1][2]
Last updated: 1/3/2013

17q23.1q23.2 microdeletion syndrome is characterized by developmental delay, microcephaly, short stature, heart defects and hand, foot and limb abnormalities.[1][2] All individuals reported to date have had mild to moderate developmental delay, in particular delays in speech. Most have had heart defects, including patent ductus arteriosus or atrial septal defects. Limb abnormalities include long, thin fingers and toes, and hypoplasia (underdevelopment) of the patellae (knee caps). Scoliosis may also be present. Many patients have also had mild and unspecific unusual facial features.[1]
Last updated: 1/3/2013

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.

Showing of 57 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Delayed speech and language development
Deficiency of speech development
Delayed language development
Delayed speech
Delayed speech acquisition
Delayed speech development
Impaired speech and language development
Impaired speech development
Language delay
Language delayed
Language development deficit
Late-onset speech development
Poor language development
Speech and language delay
Speech and language difficulties
Speech delay
[ more ]
0000750
Long fingers 0100807
Long toe
Increased length of toes
Long toes
[ more ]
0010511
Mild global developmental delay 0011342
Moderate global developmental delay 0011343
30%-79% of people have these symptoms
Frontal bossing 0002007
Intrauterine growth retardation
Prenatal growth deficiency
Prenatal growth retardation
[ more ]
0001511
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ]
0000252
Patent ductus arteriosus 0001643
Pulmonary arterial hypertension
Increased blood pressure in blood vessels of lungs
0002092
Short stature
Decreased body height
Small stature
[ more ]
0004322
5%-29% of people have these symptoms
Abnormality of epiphysis morphology
Abnormal shape of end part of bone
0005930
Atrial septal defect
An opening in the wall separating the top two chambers of the heart
Hole in heart wall separating two upper heart chambers
[ more ]
0001631
Behavioral abnormality
Behavioral changes
Behavioral disorders
Behavioral disturbances
Behavioral problems
Behavioral/psychiatric abnormalities
Behavioural/Psychiatric abnormality
Psychiatric disorders
Psychiatric disturbances
[ more ]
0000708
Bifid nose
Indentation or clefting of the nose
0011803
Bilateral single transverse palmar creases 0007598
Blepharitis
Inflammation of eyelids
0000498
Bulbous nose 0000414
Chronic otitis media
Chronic infections of the middle ear
0000389
Clinodactyly of the 5th finger
Permanent curving of the pinkie finger
0004209
Congenital contracture 0002803
Coxa magna 0003279
Depressed nasal bridge
Depressed bridge of nose
Flat bridge of nose
Flat nasal bridge
Flat, nasal bridge
Flattened nasal bridge
Low nasal bridge
Low nasal root
[ more ]
0005280
Dyspnea
Trouble breathing
0002094
Epicanthus
Eye folds
Prominent eye folds
[ more ]
0000286
Failure to thrive
Faltering weight
Weight faltering
[ more ]
0001508
Gastroesophageal reflux
Acid reflux
Acid reflux disease
Heartburn
[ more ]
0002020
Hearing impairment
Deafness
Hearing defect
[ more ]
0000365
Highly arched eyebrow
Arched eyebrows
Broad, arched eyebrows
High, rounded eyebrows
High-arched eyebrows
Thick, flared eyebrows
[ more ]
0002553
Hyperreflexia
Increased reflexes
0001347
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ]
0000316
Limitation of joint mobility
Decreased joint mobility
Decreased mobility of joints
Limited joint mobility
Limited joint motion
[ more ]
0001376
Long eyelashes
Increased length of eyelashes
Unusually long eyelashes
[ more ]
0000527
Malar flattening
Zygomatic flattening
0000272
Muscular hypotonia
Low or weak muscle tone
0001252
Narrow mouth
Small mouth
0000160
Patellar hypoplasia
Small kneecap
Underdeveloped kneecap
[ more ]
0003065
Pes planus
Flat feet
Flat foot
[ more ]
0001763
Protruding ear
Prominent ear
Prominent ears
[ more ]
0000411
Sacral dimple
Spinal dimple
0000960
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
Scoliosis 0002650
Shallow acetabular fossae 0003182
Shawl scrotum
Scrotum surrounds penis
0000049
Strabismus
Cross-eyed
Squint
Squint eyes
[ more ]
0000486
Widely spaced teeth
Wide-spaced teeth
Widely-spaced teeth
[ more ]
0000687
Percent of people who have these symptoms is not available through HPO
Abnormal facial shape
Unusual facial appearance
0001999
Aggressive behavior
Aggression
Aggressive behaviour
Aggressiveness
[ more ]
0000718
Bicuspid aortic valve
Aortic valve has two leaflets rather than three
0001647
Global developmental delay 0001263
Hypertension 0000822
Intellectual disability, mild
Mental retardation, borderline-mild
Mild and nonprogressive mental retardation
Mild mental retardation
[ more ]
0001256
Postnatal growth retardation
Growth delay as children
0008897
Slender finger
Narrow fingers
Slender fingers
thin fingers
[ more ]
0001238
Small for gestational age
Birth weight less than 10th percentile
Low birth weight
[ more ]
0001518
Sporadic
No previous family history
0003745
Talipes equinovarus
Club feet
Club foot
Clubfeet
Clubfoot
[ more ]
0001762
Showing of 57 |
Last updated: 7/1/2020

The syndrome is caused by an interstitial deletion (a deletion that does not involve the ends of a chromosome) encompassing bands 23.1 to 23.2 on the long (q) arm of chromosome 17. Two transcription factors, TBX2 and TBX4, which belong to a family of genes implicated in a variety of developmental pathways including those of heart and limbs, are found within this 2.2Mb region. This suggests that they may play a part in the symptoms seen in this condition.[1][2]  
Last updated: 1/3/2013

Parental FISH testing in most of the reported cases confirmed a de novo origin, meaning that the deletion was new to the family.[1]
Last updated: 1/3/2013

The deletion can be identified by comparative genomic hybridization (CGH) microarray and fluorescence in situ hybridization (FISH).[1]
Last updated: 1/3/2013

Testing Resources

  • Orphanet lists international laboratories offering diagnostic testing for this condition.

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


Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • Orphanet lists European clinical trials, research studies, and patient registries enrolling people with this condition. 

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 17q23.1q23.2 microdeletion syndrome. Click on the link to view a sample search on this topic.

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  1. Morichon-Delvallez N. 17q23.1q23.2 microdeletion syndrome. Orphanet. 2011; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=261279. Accessed 1/2/2013.
  2. Ballif et al. Identification of a recurrent microdeletion at 17q23.1q23.2 flanked by segmental duplications associated with heart defects and limb abnormalities. Am J Hum Genet. 2010 Mar 12;86(3):454-61. .