Jacobsen syndrome
46,XY,del(11)(q24.1)
Also known as: 11q deletion, 11q terminal deletion
46,XY,del(11)(q24.1) is the karyotype of Jacobsen syndrome, a terminal deletion of the long arm of chromosome 11. It is associated with a bleeding disorder (Paris-Trousseau thrombocytopenia), heart defects, and developmental delay.
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What the notation means
The shape of this abnormality
- (11)
- one chromosome, so one group of breakpoints follows.
- (q24.1)
- one band: everything from it out to the tip is lost (a terminal deletion).
- count · sex chromosomes
- a normal count and the usual male sex chromosomes
- abnormality
- a terminal DELETION of chromosome 11: everything distal to 11q24.1 (out to the tip) is lost
Clinical notes
del(11)(q23-q24), Jacobsen syndrome
This terminal deletion of distal 11q means Jacobsen syndrome: growth and developmental delay, characteristic facies, and the Paris-Trousseau platelet disorder from FLI1 loss, so a bleeding history belongs in the workup. Most cases arise de novo; a parental balanced rearrangement is the heritable minority worth excluding. The same FLI1, translocated rather than deleted, is the Ewing sarcoma partner.