ABSTRACT
O MPS III AHeparan-Nsulfatase
N
GlcN
s s
H2CO s
GlcNAc
O
O
R
MPS III C
COOH
CH3C Acetyl
transferase NH2
H2CO s
s
CoA
Heparan sulfate
Sanfillipo A
Heparan N-sulfatase
GlcN
s
GlcNAc
There may be differences in the severity of disease in the different types. Adult onset of dementia and minimal somatic disease have been reported in type B [21]; while dementia is commonly observed by 6 years-of-age in type A [18]. In addition, early-onset progression tends to be more rapid in type A than in types B and C. However, there is considerable heterogeneity. A particularly severe type A disease has been reported [22] from the Cayman Islands. In both types A and B, severe and mild forms of the disease have been reported in the same sibship [23,24]. Type C severity may be intermediate between that of types A and B or may present in infancy [25]. Type D is rare, but also heterogenous [26-28].
