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At a glance

Chromosome 11, partial monosomy 11q is characterized by abnormally prenatal and postnatal growth retardation, mental retardation, psychomotor retardation, craniofacial anomalies, ocular abnormalities, malformations of the hands and/or feet, and congenital heart defects (eg, ventricular septal defect).


11q-Deletion Syndrome; Partial 11q Monosomy Syndrome.


The syndrome was first identified by Danish physician Petra Jacobsen in 1973.


Approximately 1:100,000 live births.

Genetic inheritance

Autosomal dominant. Parent may carry a complete but fragile 11q chromosome. Folate deficient chromosome breakage may occur in early development, leading to full Jacobsen phenotypes. The parent may not carry the syndrome despite autosomal dominant transmission. Chromosomal deletion results in CCG repeat triplets and consequently to multiorgan involvement and dysfunctions.


The exact cause of this chromosomal deletion and triplet expansion is unknown.


Based on clinical criteria and laboratory demonstration of the deletion on the short arm of chromosome 11 (locus 11q23-24).

Clinical aspects

Present at birth with dysmorphic signs including low-set dysmorphic ears; broad, short nose with anteverted nostrils; retrognathia; U-shaped upper lip; divergent strabismus; and hammertoes and bent fingers. These children have growth and developmental retardation. Jacobsen Syndrome is associated with an isoimmune thrombocytopenia.

Precautions before anesthesia

Because of the dysmorphism affecting the nose and mouth, carefully check the airway and whether difficult airway management should be anticipated. The presence of congenital heart defect must be eliminated. Check blood count for thrombocytopenia. Check for associated abnormalities, especially of the heart and lungs. An anesthesia consultation for elective surgical procedure should be obtained.

Anesthetic considerations

Special anesthesia attention with this medical condition include airway management secondary to short neck, abnormal mouth shape, and the presence of micrognathia and retrognathia. Other important considerations include a high incidence of cardiac anomalies, and platelet dysfunction. It must be noticed that platelet abnormalities affect 95% of reported patients and involve platelet number, size, and function. Be prepared for difficult direct laryngoscopy and tracheal intubation. The proper strategy for airway management must be prepared, including different sizes laryngeal mask airway (LMA) in case of complications. Maintain spontaneous ventilation at all times until the trachea is intubated and lungs ventilated. The availability of other means of airway management (eg, fiberoptic, Bullard laryngoscope, retrograde intubation technique) must be considered to facilitate tracheal intubation. In most difficult cases, equipment for cricothyroidotomy should be available. In the more severe airway anomalies and predicted “can’t ventilate, can’t intubate” situation, the presence of an otorhinolaryngology (ORL) colleague in the operating room at the time of induction of anesthesia should be considered in case ...

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