Prenatal diagnosis of lysosomal storage diseases: A review of 23 cases

During the previous 2 yr, 23 pregnancies were monitored for the presence of 9 different lysosomal storage diseases. There were 3 possible cases of GM1 gangliosidosis, 4 of GM2 gangliosidosis Type I and one of Type II, 4 of glucosylceramidosis, 3 of sulphatide lipidosis, one of galactosylceramidosis, 2 of glycogen storage disease Type II, 2 of mucolipidosis Type II and 3 of nephropathic cystinosis. Twelve foetuses were predicted to be homozygous affected and these pregnancies were terminated. Analysis of tissues (cultured fibroblasts, brain, liver, spleen) from 11 of these foetuses confirmed the prenatal diagnosis: one foetus was lost to biochemical follow-up. Of the remaining 11 pregnancies, one terminated spontaneously (4 wk after amniocentesis). Five children have been born and considered to be unaffected by the disease for which they were at risk both by clinical and biochemical evaluation: 5 further children have not yet been tested. In 22 cases cultured amniotic cells were used for the diagnosis and sufficient cells were grown to perform the analysis before the 20th wk of gestation. In one case of mucolipidosis Type II, cells failed to proliferate in culture and cell free amniotic fluid was used for assay. It is concluded that the techniques currently employed for the above tests are diagnostic. Even so, a multidirectional approach to each diagnosis, bringing to bear all available technology in our laboratory, is still used to ensure that diagnostic errors are not made.