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.
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.
The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.
|Signs and Symptoms||Approximate number of patients (when available)|
|Bone marrow hypocellularity||90%|
|Abnormal form of the vertebral bodies||50%|
|Abnormality of the ribs||50%|
|Aplasia/Hypoplasia of the earlobes||50%|
|Aplasia/Hypoplasia of the eyebrow||50%|
|Attention deficit hyperactivity disorder||50%|
|Low-set, posteriorly rotated ears||50%|
|Preaxial foot polydactyly||50%|
|Tibial deviation of toes||50%|
|Ventricular septal defect||50%|
|Abnormality of neuronal migration||7.5%|
|Abnormality of the aorta||7.5%|
|Abnormality of the aortic valve||7.5%|
|Abnormality of the hip bone||7.5%|
|Abnormality of the palate||7.5%|
|Aplasia/Hypoplasia of the corpus callosum||7.5%|
|Cerebral cortical atrophy||7.5%|
|Hernia of the abdominal wall||7.5%|
|Hypoplastic left heart||7.5%|
|Intrauterine growth retardation||7.5%|
|Multicystic kidney dysplasia||7.5%|
|Abnormality of the eyelashes||-|
|Atria septal defect||-|
|Clinodactyly of the 5th finger||-|
|Depressed nasal bridge||-|
|Failure to thrive||-|
|Infantile muscular hypotonia||-|
|Nasolacrimal duct obstruction||-|
|Recurrent respiratory infections||-|
|U-Shaped upper lip vermilion||-|
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. Although Jacobsen syndrome is typically not inherited, an affected person can pass the deletion on to his/her children.
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.
Nonprofit support and advocacy groups bring together patients, families, medical professionals, and researchers. These groups often raise awareness, provide support, and develop patient-centered information. Many are the driving force behind research for better treatments and possible cures. They can direct people to research, resources, and services. Many groups also have experts who serve as medical advisors. Visit their website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.
Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare 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.
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Our younger daughter was born with this syndrome in 1975. Is there any evidence that the fathers of these children had commonly been regularly exposed to dangerous agricultural weedicide, pesticide and defoliant chemicals via aerial crop spraying for several years? See answer
What is the treatment for Jacobsen syndrome? Our 6 month old baby was diagnosed with this last week. See answer
I have a few questions related to Jacobsen syndrome. Do children with this condition have any issues related to fine and/or gross motor skills? Are there problems with speech or social skills? Do they always have intellectual disabilities? If so, what level of intellectual disability is expected? See answer