GM1 gangliosidosis is a severe neurological disorder occuring mainly in early infancy. Morquio B disease is the milder clinical variant and manifests primarily as a skeletal dysplasia.
Enzyme activity is essentially undetectable in both presentations.
Upon cleavage by the enzyme, 4-methylumbelliferone is released and can be quantified fluorimetrically. Turn around time is 3-5 days. Prenatal diagnosis can be performed on cultured amniotic fluid cells or chorionic villus cells. Prior contact with the laboratory is required before submitting any samples for prenatal diagnosis. Let sample stand 20-30 min., centrifuge and draw off serum.