The distinction between arylsulphatases in chorionic villi.

Area of Science:

• Biochemistry
• Medical Genetics
• Prenatal Diagnostics

Background:

• Arylsulphatase C (ASC) exhibits high activity in placental tissue.
• Assaying arylsulphatase A (ASA) and arylsulphatase B (ASB) in chorionic villus sampling (CVS) can be complicated by ASC activity.
• Misdiagnosis of lysosomal storage diseases like metachromatic leukodystrophy is a concern.

Purpose of the Study:

• To investigate methods for distinguishing ASC activity from ASA and ASB in CVS.
• To evaluate the impact of different CVS preparation techniques on arylsulphatase enzyme activities.
• To establish reliable enzyme assays for prenatal diagnosis.

Main Methods:

• Enzyme activity assays were performed on direct chorionic villi and cultured villi cells.
• Two distinct methods for preparing cultured villi cells were employed: minced villi and enzymatic digestion (trypsin and collagenase).
• Activities of ASC, ASA, and ASB were measured using synthetic substrates.

Main Results:

• A clear distinction between ASC, ASA, and ASB activities was achievable in both direct and cultured villi cells.
• ASC activity showed significant variation in cultured villi cells depending on the preparation method.
• ASA and ASB activities remained unaffected by the different cell preparation techniques.

Conclusions:

• Precise definition and standardization of chorionic villus sampling (CVS) preparations are crucial for accurate enzyme activity correlation.
• Enzyme assay results must consider the methodology used for preparing CVS samples, particularly for ASC.
• Standardized CVS preparation protocols are essential for reliable prenatal diagnosis of arylsulphatase deficiencies.