Molecular analysis of cell lines from patients with mucolipidosis II and mucolipidosis III.

Mucolipidosis II and III are autosomal recessive disorders due to mutations in the GNPTAB and GNPTG genes encoding the alphabeta- and gamma-subunits of the GlcNAc-1-phosphotransferase, respectively. This protein has a subunit structure of alpha(2)beta(2)gamma(2) and initiates the first step of tagging lysosomal enzymes with mannose-6-phosphate (M6P). In the present study, we screened four MLII and three MLIII cell lines for mutations in GNPTAB and GNPTG.