Lysosomal storage diseases in non-immune hydrops fetalis pregnancies.
BACKGROUND
At least 20 inborn errors of metabolism may cause hydrops fetalis. Most of these are lysosomal storage diseases. The study proposes a diagnostic flowchart for prenatal diagnosis of non-immune hydrops fetalis.


METHODS
This study contains a series of 75 non-immune hydrops fetalis pregnancies. Mucopolysaccharides, oligosaccharides, neuraminic acid and 21 lysosomal enzymes were measured in amniotic fluid and cultured amniotic cells.


RESULTS
The study gives reference values for mucopolysaccharides and neuraminic acid at various stages of gestation. Four definite and two probable lysosomal diagnoses were found among the 75 investigated cases (=5.3-8%). Fetal death was found to cause false positive values for mucopolysaccharides in amniotic fluid. In the galactosialidosis case, two novel mutations were found in the cathepsin A gene.


CONCLUSIONS
Reference values for mucopolysaccharides and neuraminic acid depend on gestational age. In a relatively high percentage of the hydrops foetalis pregnancies, a lysosomal aetiology is found. This study provides a strategy to diagnose lysosomal diseases in hydrops fetalis pregnancies. Awareness of lysosomal storage diseases causing hydrops fetalis is useful as it gives an opportunity for risk evaluation, genetic counseling to parents and targeted prenatal diagnostics for ensuing pregnancies.
Kooper
Angelique J A
AJ
Department of Human Genetics, division Cytogenetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
Janssens
Pim M W
PM
de Groot
Akosua N J A
AN
Liebrand-van Sambeek
Maria L F
ML
van den Berg
Catharina J M G
CJ
Tan-Sindhunata
Gita B
GB
van den Berg
Paul P
PP
Bijlsma
Emilia K
EK
Smits
Arie P T
AP
Wevers
Ron A
RA