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Hunter Syndrome ERT Helps But Many Problems Persist

FEBRUARY 14, 2017
RDR Staff
At WORLDSymposium, Broomfield et al performed a retrospective review of all Hunter syndrome [mucopolysaccharidosis (MPS) II] patients managed at Royal Manchester Children's Hospital, Manchester, United Kingdom since the commercial introduction of Elaprase (idursulfase).
 
Of the 67 in which data was available:
24 (36%) died with a median age of death = 13.75 years (0.53 to 22.03),
43 survived with median age of 14.76 years (1.25 to 24.78).
 
Of the 24 patients who died:
14 were not offered Elaprase due to excessively advanced disease (13/14) /undergoing bone marrow transplantation.  The median age of death was 9.75 years (0.53 to 19.23).
10 were given Elaprase. Their median age of death was 14.32 years (9.65 to 22) (P = .017).
 
In 9 patients, Elaprase was withdrawn. The average survival post withdrawal of Elaprase was 3.75 years (0.5 to 9 years).
 
Three patients received bone marrow transplant. Of those, 1 died and 2 survived. 


Neurological Outcomes

Neurological outcomes were available in 50 of the 67 patients.
28 were unable to attend formal schooling.
22 were able to attend school. IQ varied greatly in this group from below 85 to 140.
 
Seizures were seen in 18 of the 67 patients. Of these,  14 died.
 
Some patients required neurosurgical procedures.
 
1requiring shunting for hydrocephalus
3 lumbar spine decompression
1 cervical spine decompression.

Other surgeries/medical issues

6 patients have required tracheostomies (5 died),
18 patients have aortic valve disease
27 having mitral valve disease,
 
The authors concluded that while Elaprase (idursulfase) has significantly impacted MPS II patients’ survival, there is still significant morbidity with the potential range of neurological outcomes being under-represented in literature.

About Hunter Syndrome

Hunter syndrome, also known as mucopolysaccharidosis type II, or MPS II, is a lysosomal storage disorder caused by inadequate activity of the enzyme iduronate-2-sulfatase (IDS), which is needed to break down complex sugars produced by the body. The buildup of these complex sugars, known as mucopolysaccharides, interferes with functioning of certain cells and organs, leading to serious complications including developmental delays and mental impairment.

Reference

Broomfield A, Roberts J, Schwahn B, et al. A single center's 10-year experience of idursulfase in MPS II. Presented at the 13th Annual WORLDSymposium; February 13-17, 2016; San Diego, CA. http://dx.doi.org/10.1016/j.ymgme.2016.11.055


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