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 (e.g.,
ventricular septal defect).
11q-Deletion Syndrome; Partial 11q Monosomy Syndrome.
Approximately 1:100,000 live births.
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 leading to CCG repeat triplets and multiorgan
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).
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.
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.
Use safe airway control strategy. Be
prepared for difficult direct laryngoscopy and tracheal intubation. Maintain
spontaneous ventilation until the trachea is intubated and lungs ventilated.
A laryngeal mask should be available. Be prepared to use other means of airway management (e.g., fiberoptic,
Bullard laryngoscope, retrograde intubation technique) to facilitate tracheal intubation. In most
difficult cases, equipment for cricothyroidotomy should be available. Only
then, if necessary, can a muscle relaxant be used. The anesthetic management
also is dictated by the presence of congenital anomalies of the heart.
Strict asepsis must be provided because of immune system defect.
No specific implications with this
Paris-Trousseau Syndrome: Hematologic disorder associating
low platelet count and abnormal platelet function. The intriguing fact is
that all known patients with Jacobsen Syndrome have Paris-Trousseau Syndrome
(which seems to be a variant of Jacobsen Syndrome, with the same gene map
Chromosome 11 Ring: Caused by a break of the long and
short arms of chromosome 11. It is characterized by failure to thrive,
psychomotor retardation, craniofacial anomalies (e.g., microbrachycephaly,
short nose with a low, depressed nasal bridge, microretrognathism, low-set
ears), ocular abnormalities, a short neck, pancytopenia, and congenital
heart defects. The exact cause of chromosome 11 ring is not fully
C Syndrome: Characterized by a “triangular-shaped”
head with trigonocephaly resulting from severe craniosynostosis. Other
clinical features include craniofacial anomalies, a short nose with a broad
nasal bridge, epicanthus, cleft palate, and low-set, malformed ears. Joint