LSDDB

Mucopolysaccharidoses Ⅳ B

This type of MPs is also called as Morquio type B. It is caused due to the defective activity of enzyme β-galactosidase gene (GLB). The GLB1 gene is located at 3p22.3 (Pshezhetsky and Ashmarina, 2001). Mutations in this gene results in two disorders;
1) GM1 gangliosidosis which is not an MPS.
2) MPS Ⅳ type B.
Both disorders are clinically difficult to identify but present with late onset mental manifestations and presence of keratin sulfate in urine in case of GM 1 gangliosidosis (Oshima et al., 1991).

Reference :
Oshima, A. et al. (1991) ‘Human beta-galactosidase gene mutations in morquio B disease’, American Journal of Human Genetics, 49(5), pp. 1091–1093.
Pshezhetsky, A. V. and Ashmarina, M. (2001) ‘Lysosomal multienzyme complex: Biochemistry, genetics, and molecular pathophysiology’, in Progress in Nucleic Acid Research and Molecular Biology. Academic Press, pp. 81–114. doi: 10.1016/S0079-6603(01)69045-7.