Isodicentric chromosome 15 syndrome

Title

Other Names:

Duplication/inversion 15q11; Inv dup(15); Non-distal tetrasomy 15q; Duplication/inversion 15q11; Inv dup(15); Non-distal tetrasomy 15q; Non-telomeric tetrasomy 15q; Idic(15); Tetrasomy 15q; Chromosome 15q tetrasomy; Inverted duplication 15 See More

Categories:

Congenital and Genetic Diseases; Nervous System Diseases

This disease is grouped under:

Chromosome 15q duplication

Summary Summary

Isodicentric chromosome 15 syndrome is a chromosome abnormality that affects many different parts of the body. As the name suggests, people with this condition have an extra chromosome (called an isodicentric chromosome 15) which is made of two pieces of chromosome 15 that are stuck together end-to-end. Although the severity of the condition and the associated features vary from person to person, common signs and symptoms include poor muscle tone in newborns; developmental delay; mild to severe intellectual disability; delayed or absent speech; behavioral abnormalities; and seizures.^[1]^[2] Most cases of isodicentric chromosome 15 syndrome occur sporadically in people with no family history of the condition.^[3]^[1] Treatment is based on the signs and symptoms present in each person.^[1]

Last updated: 1/21/2016

Symptoms Symptoms

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	Learn More: HPO ID
80%-99% of people have these symptoms
Autistic behavior		0000729
Drooling	Dribbling	0002307
Generalized hypotonia	Decreased muscle tone Low muscle tone [ more ]	0001290
Joint hypermobility	Double-Jointed Flexible joints Increased mobility of joints [ more ]	0001382
30%-79% of people have these symptoms
Echolalia	Echoing another person's speech	0010529
Feeding difficulties	Feeding problems Poor feeding [ more ]	0011968
Hyperactivity	More active than typical	0000752
Seizures	Seizure	0001250
Self-biting		0012169
Severe expressive language delay		0006863
Severe receptive language delay		0011352
Stereotypy	Repetitive movements Repetitive or self-injurious behavior [ more ]	0000733
5%-29% of people have these symptoms
2-3 toe syndactyly	Webbed 2nd and 3rd toes	0004691
Abnormal facial shape	Unusual facial appearance	0001999
Aggressive behavior	Aggression Aggressive behaviour Aggressiveness [ more ]	0000718
Brachycephaly	Short and broad skull	0000248
Brachydactyly	Short fingers or toes	0001156
Broad nasal tip	Broad tip of nose Broad, upturned nose Increased breadth of nasal tip Increased breadth of tip of nose Increased width of nasal tip Increased width of tip of nose Nasal tip, broad Nasal tip, wide Wide tip of nose [ more ]	0000455
Clinodactyly of the 5th finger	Permanent curving of the pinkie finger	0004209
Deeply set eye	Deep set eye Deep-set eyes Sunken eye [ more ]	0000490
Downslanted palpebral fissures	Downward slanting of the opening between the eyelids	0000494
Epicanthus	Eye folds Prominent eye folds [ more ]	0000286
Growth delay	Delayed growth Growth deficiency Growth failure Growth retardation Poor growth Retarded growth [ more ]	0001510
High palate	Elevated palate Increased palatal height [ more ]	0000218
Hypogonadism	Decreased activity of gonads	0000135
Low-set, posteriorly rotated ears		0000368
Microcephaly	Abnormally small skull Decreased circumference of cranium Decreased size of skull Reduced head circumference Small head circumference [ more ]	0000252
Short philtrum		0000322
Strabismus	Cross-eyed Squint Squint eyes [ more ]	0000486
Synophrys	Monobrow Unibrow [ more ]	0000664
1%-4% of people have these symptoms
Cryptorchidism	Undescended testes Undescended testis [ more ]	0000028
Gonadal dysgenesis		0000133
Hernia		0100790
Precocious puberty	Early onset of puberty Early puberty [ more ]	0000826
Talipes equinovarus	Club feet Club foot Clubfeet Clubfoot [ more ]	0001762
Tetralogy of Fallot		0001636
Unilateral renal agenesis	Absent kidney on one side Missing one kidney Single kidney [ more ]	0000122
Ventricular septal defect	Hole in heart wall separating two lower heart chambers	0001629

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Do you have more information about symptoms of this disease? We want to hear from you.

Last updated: 3/1/2020

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Related Diseases Related Diseases

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
The possible occurrence of double supernumerary isodicentric chromosomes derived from chromosome 15, resulting in partial hexasomy of the maternally inherited PWS/ASCR, should be considered in the differential diagnosis. Visit the Orphanet disease page for more information.

Organizations Organizations

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

Chromosome Disorder Outreach (CDO)
PO Box 724
Boca Raton, FL 33429
Telephone: +1-561-395-4252
E-mail: https://chromodisorder.org/contact/
Website: https://chromodisorder.org/
Dup15q Alliance
P.O. Box 1669
Highland Park, IL 60035
Telephone: 855-dup-15qa
E-mail: info@dup15q.org
Website: http://www.dup15q.org/
IDIC15 Canada
Canada
Telephone: 250-320-5877 or 778-989-1210
E-mail: info@idic15canada.ca
Website: http://www.idic15canada.ca/
Unique – Rare Chromosome Disorder Support Group
G1, The Stables
Station Road West
Surrey
RH8 9EE
United Kingdom
Telephone: +44 (0)1883 723356
E-mail: info@rarechromo.org
Website: https://www.rarechromo.org/

Do you know of an organization? We want to hear from you.

Learn More Learn More

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.

Where to Start

Genetics Home Reference (GHR) contains information on Isodicentric chromosome 15 syndrome. This website is maintained by the National Library of Medicine.
Unique is a source of information and support for families and individuals affected by rare chromosome disorders. Click on the link to view information about Isodicentric chromosome 15 syndrome.

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.
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 Isodicentric chromosome 15 syndrome. Click on the link to view a sample search on this topic.

GARD Answers GARD Answers

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.

Have a question? Contact a GARD Information Specialist.

References References

Idic(15). Unique. 2014; http://www.rarechromo.org/information/Chromosome%2015/Idic%2815%29%20FTNW.pdf.
Rim JH, Chung HJ, Shin S, Park SJ, Choi JR. Isodicentric Chromosome 15 Syndrome in a Korean Patient With Café-au-lait Spots. Ann Lab Med. July 2015; 35(4):474-476.
Isodicentric chromosome 15 syndrome. Genetics Home Reference. September 2012; http://ghr.nlm.nih.gov/condition/isodicentric-chromosome-15-syndrome.

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