Chromosome 11, Partial Trisomy 11q

National Organization for Rare Disorders, Inc.

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It is possible that the main title of the report Chromosome 11, Partial Trisomy 11q is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.


  • 11q Partial Trisomy
  • Chromosome 11, Partial Trisomy 11q13-qter
  • Chromosome 11, Partial Trisomy 11q21-qter
  • Chromosome 11, Partial Trisomy 11q23-qter
  • Distal Trisomy 11q
  • Partial Trisomy 11q
  • Trisomy 11q, Partial

Disorder Subdivisions

  • None

General Discussion

Chromosome 11, Partial Trisomy 11q is a rare chromosomal disorder in which the end (distal) portion of the long arm (q) of the 11th chromosome appears three times (trisomy) rather than twice in cells of the body. Although associated symptoms and findings may vary, the disorder is often associated with delayed growth before and after birth (prenatal and postnatal growth retardation); varying degrees of mental retardation; distinctive abnormalities of the skull and facial (craniofacial) region; and/or other features. Chromosomal analysis is necessary for a definite diagnosis.


Chromosome 11, Partial Trisomy 11q is commonly characterized by growth retardation before and after birth, delayed acquisition of skills requiring the coordination of mental and motor activities (psychomotor retardation), mild to moderate mental retardation, and distinctive craniofacial abnormalities.

In individuals with Partial Trisomy 11q, craniofacial abnormalities may include an abnormally small head (microcephaly) that may appear unusually short and broad (brachycephaly); a short nose; low-set ears; and/or incomplete closure of the roof of the mouth (cleft palate) or a highly arched palate. Many affected individuals also have abnormal pits or depressions and/or outgrowths of skin and cartilage in front of the ears (preauricular pits or tags); a small jaw (micrognathia); a retracted lower lip; and/or an unusually long vertical groove in the center of the upper lip (philtrum). Additional craniofacial features may sometimes include widely spaced eyes (ocular hypertelorism); downwardly slanting eyelid folds (palpebral fissures); vertical skin folds over the eyes' inner corners (epicanthal folds); and/or abnormal deviation of one eye in relation to the other (strabismus). In addition, in some cases, one side of the face may appear smaller than or relatively dissimilar to the other (facial asymmetry).

In some affected individuals, Chromosome 11, Partial Trisomy 11q may also be associated with additional physical findings. These may include skeletal abnormalities, such as malformation of the collarbone (clavicular defect) and/or dislocation or improper development (dysplasia) of the hips; structural malformations of the heart that are present at birth (congenital heart defects); and/or underdevelopment or absence of the band of nerve fibers that normally joins the two hemispheres of the brain (hypoplasia or agenesis of the corpus callosum). Additional abnormalities that have been reported in association with Partial Trisomy 11q have included an unusually short neck; abnormal looseness of the skin (cutis laxa); abnormal creases on the palms of the hands; or undescended testes (cryptorchidism) and/or an unusually small penis (micropenis) in affected males.


In individuals with Chromosome 11, Partial Trisomy 11q, the end (distal) region of the long arm (q) of chromosome 11 is present three times (i.e., trisomic or duplicated) rather than twice in cells of the body. Chromosomes are found in the nucleus of all body cells. They carry the genetic characteristics of each individual. Pairs of human chromosomes are numbered from 1 through 22, with an unequal 23rd pair of X and Y chromosomes for males and two X chromosomes for females. Each chromosome has a short arm designated as "p" and a long arm identified by the letter "q." Chromosomes are further subdivided into bands that are numbered.

Evidence suggests that Partial Trisomy 11q typically results from a translocation involving chromosome 11q and another chromosome, usually chromosome 22q. Translocations occur when regions of certain chromosomes break off and are rearranged, resulting in shifting of genetic material and an altered set of chromosomes. In individuals with Partial Trisomy 11q, such translocations most commonly appear to be transmitted by a parent who is a carrier of a "balanced" translocation. If a chromosomal rearrangement is balanced, meaning that it consists of an altered but balanced set of chromosomes, it is usually harmless to the carrier. However, such a chromosomal rearrangement may be associated with an increased risk of abnormal chromosomal development in the carrier's offspring. Chromosomal analysis may determine whether a parent has a balanced translocation. In a few cases, chromosomal rearrangements resulting in Partial Trisomy 11q have appeared to occur spontaneously for unknown reasons (de novo). In such cases, the parents of the affected child usually have normal chromosomes and a relatively low risk of having another child with the chromosomal abnormality.

Affected Populations

Chromosome 11, Partial Trisomy 11q is a very rare chromosomal disorder that is reported to affect more females than males. Approximately 45 cases of this disorder have been documented in the medical literature.

Standard Therapies


Chromosome 11, Partial Trisomy 11q may be diagnosed through genetic testing, either during pregnancy (prenatally) or after birth (postnatally). Prenatal procedures such as amniocentesis, chorionic villus sampling, and fetal blood sampling involve chromosomal analysis of fluid and/or tissue samples extracted from the fetus or the uterus during pregnancy (prenatally).


Treatment of Chromosome 11, Partial Trisomy 11q is symptomatic and supportive. Special education, physical therapy, and other medical, social, or vocational services are of benefit to the affected individual, and are often necessary for the child to reach his/her full potential. Genetic counseling will be of benefit for affected individuals and their families.

Investigational Therapies

Information on current clinical trials is posted on the Internet at All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222

TTY: (866) 411-1010


For information about clinical trials sponsored by private sources, contact:



Buyse ML. Birth Defects Encyclopedia. Dover, MA: Blackwell Scientific Publications, Inc.; 1990:362-63.

Gorlin RJ, et al., eds. Syndromes of the Head and Neck. 3rd ed. New York, NY: Oxford University Press; 1990:86.


Wallerstein R, et al. Partial trisomy 11q in a female infant with Robin sequence and congenital heart disease. Cleft Palate Craniofac J. 1992;29:77-79.

Greig F, et al. Duplication 11 (q22--->qter) in an infant. A case report with review. Ann Genet. 1985;28:185-88.

Pihko H, et al. Partial 11q trisomy syndrome. Hum Genet. 1981;58:129-34.

Ayraud N, et al. Trisomy 11q (q23.1 - qter) through maternal translocation t(11;22) (q23.1;q11.1). A new case. Ann Genet. 1976;19:65-68.

Aurias A, et al. 2 cases of trisomy 11q(q231--qter) by translocation t(11;22) (q231;q111) in 2 different families. Ann Genet. 1975;18:185-88.


Children's Craniofacial Association

13140 Coit Road

Suite 517

Dallas, TX 75240


Tel: (214)570-9099

Fax: (214)570-8811

Tel: (800)535-3643



Support Organization for Trisomy 18, 13, and Related Disorders

2982 S. Union Street

Rochester, NY 14624-1926

Fax: (585)594-1957

Tel: (800)716-7638



March of Dimes Birth Defects Foundation

1275 Mamaroneck Avenue

White Plains, NY 10605

Tel: (914)997-4488

Fax: (914)997-4763


The Arc

1825 K Street NW, Suite 1200

Washington, DC 20006

Tel: (202)534-3700

Fax: (202)534-3731

Tel: (800)433-5255

TDD: (817)277-0553




PO Box 751112

Las Vegas, NV 89136


Tel: (702)769-9264

Fax: (702)341-5351

Tel: (888)486-1209



Chromosome Disorder Outreach, Inc.

P.O. Box 724

Boca Raton, FL 33429-0724


Tel: (561)395-4252

Fax: (561)395-4252



American Heart Association

7272 Greenville Avenue

Dallas, TX 75231

Tel: (214)784-7212

Fax: (214)784-1307

Tel: (800)242-8721



UNIQUE - Rare Chromosome Disorder Support Group


The Rare Chromosome Disorder Support Group

G1 The Stables

Station Road West, Oxted

Surrey, RH8 9EE

United Kingdom

Tel: 441883723356

Email: or


Craniofacial Foundation of America

975 East Third Street

Chattanooga, TN 37403

Tel: (423)778-9176

Fax: (423)778-8172

Tel: (800)418-3223



European Chromosome 11q Network

Sparkasse Pforzheim D

Wiernsheim, 85421


Tel: 31317423345

Fax: 31317426980



Genetic and Rare Diseases (GARD) Information Center

PO Box 8126

Gaithersburg, MD 20898-8126

Tel: (301)251-4925

Fax: (301)251-4911

Tel: (888)205-2311

TDD: (888)205-3223


For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders, Inc.® (NORD). Cigna members can access the complete report by logging into For non-Cigna members, a copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see