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Disease Profile

Jacobsen syndrome

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

US Estimated

Europe Estimated

Age of onset

Antenatal

ICD-10

Q93.5

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

JBS; Chromosome 11q deletion syndrome; Partial 11q monosomy syndrome

Categories

Blood Diseases; Chromosome Disorders; Congenital and Genetic Diseases;

Summary

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]

Symptoms

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]

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.

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

Cause

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]

Diagnosis

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.

    Treatment

    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]

    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

      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

      • Unique the Rare Chromosome Disorder Support Group is a source of information and support to families and individuals affected by rare chromosome disorders. Click on the link to view information related to Jacobsen syndrome.
      • MedlinePlus Genetics contains information on Jacobsen syndrome. This website is maintained by the National Library of Medicine.
      • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

        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.

            References

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

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