The affected children have deletions on chromosome 11 as well as some extra genetic material from another chromosome.Ring chromosome 11- in this case genetic material from both long and short arm of the chromosome get deleted, and the remaining part joins and forms a ring like structure. Here the affected person would have symptoms associated with both 11q and 11p deletion. Genetics
If de novo deletion occurs then both the parents have normal chromosomes, and chances that another child will have the deletion decline. Very few cases have been found in which the deletion has been present in mosaic form (where some of the cells have deletion on chromosome 11 and some do not, and the symptoms are less severe) in one of the parents, which increases the risk of having another child with Jacobsen syndrome. When the childs chromosomal abnormality occurs due to one of the parents balanced translocation, the chances of another child having the abnormality is high. Diagnosis
Diagnosing Jacobsen syndrome can be difficult in some cases because it is a rare chromosomal disorder. There are a variety of tests that can be carried out, like karyotypes, cardiac echocardiograms, a renal sonogram, a platelet count, blood counts, a brain imaging study. Genetic testing can be carried out for diagnosis. Here chromosomes are stained to give a barcode like appearance and studied under the microscope, which reveals the broken and deleted genes. The condition can also be diagnosed early in the prenatal stage if there are any abnormalities seen in the ultrasound.
Imiglucerase is a medication used in the treatment of Gauchers disease.It is a recombinant DNA-produced analogue of the human enzyme β-glucocerebrosidase. Cerezyme is a freeze-dried medicine containing imiglucerase, manufactured by Genzyme Corporation. It is given intravenously after reconstitution as a treatment for Type 1 and Type 3 Gauchers disease. It is available in formulations containing 200 or 400 units per vial. The specific activity of highly purified human enzyme is 890,000 units/mg, meanwhile the enzyme activity produced by recombinant DNA technology is approximately 40 units/mg. A typical dose is 2.5U/kg every two weeks, up to a maximum of 60 U/kg once every two weeks, and safety has been established from ages 2 and up. It is one of more expensive medications, with an annual cost of $200,000 per person in the United States. Imiglucerase has been granted orphan drug status in the United States, Australia, and Japan.Cerezyme was one of the drugs manufactured at Genzymes Allston, Massachusetts plant, for which production was disrupted in 2009 after contamination with Vesivirus 2017. Side effects
The most common side effect is hypersensitivity, which occurs in about 3% of patients. It is associated with symptoms such as cough, shortness of breath, rashes, itching, and angiooedema. Less common side effects include dizziness, headache, nausea, diarrhoea, and reactions at the injection site; they are found in less than 1% of patients. Interactions
No clinical interaction studies have been conducted. Miglustat appears to increase the clearance of imiglucerase by 70%, resulting in decreased enzyme activity.