Mucolipidosis II (I cell disease). First case report in the Czech Republic and prenatal diagnosis in a family

The authors describe the first case of mucolipidosis II in the Czech Republic. The cause of this autosomal recessive hereditary disease is deficient synthesis of mannoso-6-phosphate ligand on precursors of lysosomal enzymes which normally make their transport into the lysosomal system possible. The diagnosis was proved by the presence of typical lysosomal cumulation in bioptic specimens and extremely elevated activity of lysosomal enzymes in the patient's serum caused by their non-regulated secretion and subsequent intracellular depletion. During the second pregnancy in the family prenatal diagnosis was made. A normal range of lysosomal enzyme activities in the supernatant of the amniotic fluid and in cultivated chorionic villi along with normal results of ultrastructural examination of the chorionic villus indicated the development of an intact foetus.