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Genetic and Rare Diseases Information Center (GARD)

Jacobsen syndrome

Other Names for this Disease
  • JBS
  • Chromosome 11q deletion syndrome
  • Partial 11q monosomy syndrome
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.


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What are the signs and symptoms of Jacobsen syndrome?

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

The Human Phenotype Ontology provides the following list of signs and symptoms for Jacobsen syndrome. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms.

Signs and Symptoms Approximate number of patients (when available)
Bone marrow hypocellularity 90%
Cognitive impairment 90%
Thrombocytopenia 90%
Abnormal form of the vertebral bodies 50%
Abnormality of the ribs 50%
Anteverted nares 50%
Aplasia/Hypoplasia of the earlobes 50%
Aplasia/Hypoplasia of the eyebrow 50%
Attention deficit hyperactivity disorder 50%
Broad columella 50%
Constipation 50%
Cryptorchidism 50%
Epicanthus 50%
Facial asymmetry 50%
Finger syndactyly 50%
Frontal bossing 50%
High forehead 50%
Hypertelorism 50%
Long hallux 50%
Long philtrum 50%
Low-set, posteriorly rotated ears 50%
Macrocephaly 50%
Pes planus 50%
Preaxial foot polydactyly 50%
Premature birth 50%
Ptosis 50%
Short neck 50%
Short nose 50%
Short stature 50%
Short toe 50%
Strabismus 50%
Tibial deviation of toes 50%
Toe syndactyly 50%
Ventricular septal defect 50%
Ventriculomegaly 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%
Annular pancreas 7.5%
Aplasia/Hypoplasia of the corpus callosum 7.5%
Cataract 7.5%
Cerebral cortical atrophy 7.5%
Cleft eyelid 7.5%
Duodenal stenosis 7.5%
Ectopic anus 7.5%
Eczema 7.5%
Hand polydactyly 7.5%
Hernia of the abdominal wall 7.5%
Hypoplastic left heart 7.5%
Intestinal malrotation 7.5%
Intrauterine growth retardation 7.5%
Iris coloboma 7.5%
Multicystic kidney dysplasia 7.5%
Pyloric stenosis 7.5%
Scoliosis 7.5%
Seizures 7.5%
Spina bifida 7.5%
Talipes 7.5%
Trigonocephaly 7.5%
Urogenital fistula 7.5%
Webbed neck 7.5%
Abnormality of the eyelashes -
Amblyopia -
Atria septal defect -
Brachydactyly syndrome -
Chorioretinal coloboma -
Clinodactyly of the 5th finger -
Clitoral hypoplasia -
Depressed nasal bridge -
Failure to thrive -
Flat occiput -
Flexion contracture -
Holoprosencephaly -
Hydrocephalus -
Hypospadias -
Infantile muscular hypotonia -
Intellectual disability -
Labial hypoplasia -
Low-set ears -
Macular hypoplasia -
Microcephaly -
Microcornea -
Microphthalmia -
Missing ribs -
Nasolacrimal duct obstruction -
Optic atrophy -
Pectus excavatum -
Recurrent respiratory infections -
Spasticity -
Sporadic -
Telecanthus -
U-Shaped upper lip vermilion -

Last updated: 7/1/2016

The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature.

The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined.

Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.

  1. Jacobsen syndrome. Genetics Home Reference (GHR). 2009;

Other Names for this Disease
  • JBS
  • Chromosome 11q deletion syndrome
  • Partial 11q monosomy syndrome
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.