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

Jacobsen syndrome


Other Names:
JBS; Chromosome 11q deletion syndrome; Partial 11q monosomy syndrome
Categories:
Jacobsen syndrome is a condition characterized by the deletion of several genes on chromosome 11. Signs and symptoms vary among affected people but often include Paris-Trousseau syndrome (a bleeding disorder); distinctive facial features; delayed development of motor skills and speech; and cognitive impairment. Other features may include compulsive behavior; attention deficit-hyperactivity disorder (ADHD); congenital heart defects; short stature; and/or skeletal abnormalities. In most cases, the deletion that causes Jacobsen syndrome is not inherited and occurs randomly due to an error in cell division. In some cases, an affected person inherits the deletion from an unaffected parent with a balanced translocation. Treatment depends on the specific symptoms in each affected person.[1]
Last updated: 6/22/2015
The signs and symptoms of Jacobsen syndrome can vary. Most affected people have delayed development of motor skills and speech; cognitive impairment; and learning difficulties. Behavioral features have been reported and may include compulsive behavior; a short attention span; and distractibility. Many people with the condition are diagnosed with attention deficit-hyperactivity disorder (ADHD). The vast majority of people with Jacobsen syndrome also have a bleeding disorder called Paris-Trousseau syndrome, which causes abnormal bleeding and easy bruising. [1]

People with Jacobsen syndrome typically have distinctive facial features, which include small and low-set ears; wide-set eyes (hypertelorism) with droopy eyelids (ptosis); skin folds covering the inner corner of the eyes; a broad nasal bridge; down-turned corners of the mouth; a thin upper lip; and a small lower jaw (micrognathia). Affected people often have a large head (macrocephaly) and a skull abnormality called trigonocephaly, giving the forehead a pointed appearance.[1]

Other signs and symptoms of the condition may include congenital heart defects; short stature; feeding difficulties in infancy; frequent ear and sinus infections; and skeletal (bone) abnormalities.[1]
Last updated: 6/22/2015

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 103 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Bone marrow hypocellularity
Bone marrow failure
0005528
Feeding difficulties in infancy 0008872
Global developmental delay 0001263
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Thrombocytopenia
Low platelet count
0001873
30%-79% of people have these symptoms
Abnormal form of the vertebral bodies 0003312
Anteverted nares
Nasal tip, upturned
Upturned nasal tip
Upturned nose
Upturned nostrils
[ more ] 		0000463
Aplasia/Hypoplasia of the earlobes
Absent/small ear lobes
Absent/underdeveloped ear lobes
[ more ] 		0009906
Aplasia/Hypoplasia of the eyebrow
Absence of eyebrow
Lack of eyebrow
Missing eyebrow
[ more ] 		0100840
Attention deficit hyperactivity disorder
Attention deficit
Attention deficit disorder
Attention deficit-hyperactivity disorder
Attention deficits
Childhood attention deficit/hyperactivity disorder
[ more ] 		0007018
Broad columella 0010761
Broad hallux phalanx
Broad bone of big toe
Wide bone of big toe
[ more ] 		0010059
Constipation 0002019
Cryptorchidism
Undescended testes
Undescended testis
[ more ] 		0000028
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
Epicanthus
Eye folds
Prominent eye folds
[ more ] 		0000286
Facial asymmetry
Asymmetry of face
Crooked face
Unsymmetrical face
[ more ] 		0000324
Finger syndactyly 0006101
Frontal bossing 0002007
High forehead 0000348
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ] 		0000316
Long hallux
Long big toe
0001847
Long philtrum 0000343
Low-set, posteriorly rotated ears 0000368
Macrocephaly
Increased size of skull
Large head
Large head circumference
[ more ] 		0000256
Microcornea
Cornea of eye less than 10mm in diameter
0000482
Missing ribs
Absent ribs
Decreased rib number
[ more ] 		0000921
Pes planus
Flat feet
Flat foot
[ more ] 		0001763
Premature birth
Premature delivery of affected infants
Preterm delivery
[ more ] 		0001622
Ptosis
Drooping upper eyelid
0000508
Recurrent respiratory infections
Frequent respiratory infections
Multiple respiratory infections
respiratory infections, recurrent
Susceptibility to respiratory infections
[ more ] 		0002205
Short neck
Decreased length of neck
0000470
Short nose
Decreased length of nose
Shortened nose
[ more ] 		0003196
Short stature
Decreased body height
Small stature
[ more ] 		0004322
Short toe
Short toes
Stubby toes
[ more ] 		0001831
Smooth philtrum 0000319
Strabismus
Cross-eyed
Squint
Squint eyes
[ more ] 		0000486
Toe clinodactyly 0001863
Toe syndactyly
Fused toes
Webbed toes
[ more ] 		0001770
Ventricular septal defect
Hole in heart wall separating two lower heart chambers
0001629
Ventriculomegaly 0002119
5%-29% of people have these symptoms
Abnormal palate morphology
Abnormality of the palate
Abnormality of the roof of the mouth
[ more ] 		0000174
Agenesis of corpus callosum 0001274
Annular pancreas 0001734
Aortic valve stenosis
Narrowing of aortic valve
0001650
Bipolar affective disorder
Bipolar disorder
0007302
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
Cerebral atrophy
Degeneration of cerebrum
0002059
Coarctation of aorta
Narrowing of aorta
Narrowing of the aorta
[ more ] 		0001680
Death in infancy
Infantile death
Lethal in infancy
[ more ] 		0001522
Duodenal atresia
Absence or narrowing of first part of small bowel
0002247
Ectopic anus
Abnormal anus position
0004397
Ectropion
Eyelid turned out
0000656
Eczema 0000964
Eyelid coloboma
Cleft eyelid
Notched eyelid
[ more ] 		0000625
Hand polydactyly
Extra finger
0001161
Hip dislocation
Dislocated hips
Dislocation of hip
[ more ] 		0002827
Hydronephrosis 0000126
Hypoplastic left heart
Underdeveloped left heart
0004383
Inguinal hernia 0000023
Intestinal malrotation 0002566
Intrauterine growth retardation
Prenatal growth deficiency
Prenatal growth retardation
[ more ] 		0001511
Iris coloboma
Cat eye
0000612
Multicystic kidney dysplasia 0000003
Pachygyria
Fewer and broader ridges in brain
0001302
Pyloric stenosis 0002021
Schizophrenia 0100753
Scoliosis 0002650
Seizure 0001250
Spina bifida 0002414
Talipes 0001883
Trigonocephaly
Triangular skull shape
Wedge shaped skull
[ more ] 		0000243
Webbed neck
Neck webbing
0000465
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
Percent of people who have these symptoms is not available through HPO
Abnormal eyelash morphology
Abnormal eyelashes
Abnormality of the eyelashes
Eyelash abnormality
[ more ] 		0000499
Amblyopia
Lazy eye
Wandering eye
[ more ] 		0000646
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
Brachydactyly
Short fingers or toes
0001156
Chorioretinal coloboma
Birth defect that causes a hole in the innermost layer at the back of the eye
0000567
Clinodactyly of the 5th finger
Permanent curving of the pinkie finger
0004209
Clitoral hypoplasia
Small clitoris
Underdeveloped clit
[ more ] 		0000060
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
Failure to thrive
Faltering weight
Weight faltering
[ more ] 		0001508
Flat occiput 0005469
Flexion contracture
Flexed joint that cannot be straightened
0001371
Generalized hypotonia
Decreased muscle tone
Low muscle tone
[ more ] 		0001290
Holoprosencephaly 0001360
Hydrocephalus
Too much cerebrospinal fluid in the brain
0000238
Hypospadias 0000047
Infantile muscular hypotonia
Decreased muscle tone in infant
0008947
Labial hypoplasia
Underdeveloped labia
0000066
Low-set ears
Low set ears
Lowset ears
[ more ] 		0000369
Macular hypoplasia 0001104
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ] 		0000252
Micrognathia
Little lower jaw
Small jaw
Small lower jaw
[ more ] 		0000347
Microphthalmia
Abnormally small eyeball
0000568
Nasolacrimal duct obstruction
Blocked tear duct
0000579
Optic atrophy 0000648
Pectus excavatum
Funnel chest
0000767
Spasticity
Involuntary muscle stiffness, contraction, or spasm
0001257
Sporadic
No previous family history
0003745
Telecanthus
Corners of eye widely separated
0000506
U-Shaped upper lip vermilion
Carp-like mouth
Carp-shaped mouth
Fish mouth
Large, carp-shaped mouth
Wide, carp-shaped mouth
[ more ] 		0010806
Showing of 103 |
Last updated: 7/1/2020
Jacobsen syndrome is caused by a deletion of genetic material at the end of the long (q) arm of chromosome 11. The size of the deletion varies among affected people, but the deleted area almost always includes the tip of chromosome 11. The specific features of Jacobsen syndrome relate to the loss of multiple genes within the deleted region. While the exact function of some of the genes involved is unclear, they appear to be critical for normal development of many parts of the body. In general, larger deletions cause more severe signs and symptoms than smaller deletions.[1]

In about 85% of cases, the deletion is due to a random error during the formation of the egg or sperm, or an error in cell division in early fetal development. This is called a de novo deletion. In about 15% of cases, the deletion is caused by a parent having a balanced translocation or from other, rare types of chromosome rearrangements.[2] Although Jacobsen syndrome is typically not inherited, an affected person can pass the deletion on to his/her children.[1]
Last updated: 6/22/2015

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
There is no cure for Jacobsen syndrome; treatment generally focuses on the specific signs and symptoms present in each individual. Treatment may require the coordinated efforts of a team of various specialists.

Individuals with low platelet counts (thrombocytopenia) should be monitored regularly. Blood or platelet transfusions may be necessary before or during surgeries. Surgery may be needed to repair various malformations associated with the condition. Complications of certain congenital heart defects (such as rapid heartbeat or fluid accumulation) may be treated with a variety of drugs. Respiratory infections should be treated vigorously and early. Because of the risk of bacterial infection of the heart lining (endocarditis) and valves, those with certain heart defects may need antibiotics before any surgery.

Eye abnormalities may be treated with surgery, glasses, contact lenses, and/or other measures to improve visual problems. Abnormalities of the joints, tendons, muscles, and bones may be treated by orthopedic techniques, potentially in combination with surgery. Physical therapy may help improve coordination and mobility. Early intervention is important to ensure that affected children reach their full potential.[3]
Last updated: 5/30/2012

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

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
Differential diagnoses include the Turner and Noonan syndromes (see these terms), and acquired thrombocytopenia due to sepsis. Prenatal diagnosis of 11q deletion is possible through cytogenetic analysis of amniocytes or chorionic villus samples.
Visit the Orphanet disease page for more information.

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.

Where to Start

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 Jacobsen syndrome. Click on the link to view a sample search on this topic.

Selected Full-Text Journal Articles

  • The Orphanet Journal of Rare Diseases has published an article with information on this condition. This journal is affiliated with the Orphanet reference portal for information on rare diseases and orphan drugs.

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.

  1. Jacobsen syndrome. Genetics Home Reference (GHR). 2009; http://ghr.nlm.nih.gov/condition/jacobsen-syndrome.
  2. Paul Grossfeld, Teresa Mattine, Concetta Simona Perrotta. Jacobsen syndrome. Orphanet. March, 2009; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=2308.
  3. Chromosome 11, Partial Monosomy 11q. NORD. April 26, 2012; http://rarediseases.org/rare-disease-information/rare-diseases/byID/641/viewAbstract. Accessed 5/30/2012.