Amniotic fluid α-fetoprotein microheterogeneity in the prenatal diagnosis of congenital disorders of glycosylation type Ia.
BACKGROUND
Congenital disorders of glycosylation are a group of clinically and biochemically diverse defects. The current screening method (based on analysis of transferrin), which is used postnatally for the most frequent types, is however not suitable for prenatal diagnosis. The aim of the study was to investigate whether alterations in the microheterogeneity of α-fetoprotein would provide more reliable results.


METHODS
During the 14th-19th weeks of gestation, 140 amniotic fluid samples were obtained by amniocentesis and tested for fetal developmental abnormalities. α-Fetoprotein was analyzed using isoelectric focusing on Immobiline DryPlate pH 4-7, rehydrated in urea (8 mol/L), and molecular forms of the glycoprotein were detected by immunofixation and silver staining.


RESULTS
A difference in the relative proportion of individual α-fetoprotein bands (particularly increase of band II density) was found in a case where a congenital disorder of glycosylation was diagnosed postnatally, and in two other samples from pregnancies which resulted in termination, without further examination.


CONCLUSIONS
Our potential for further testing is limited; thus far, no other congenital disorders of glycosylation-positive samples have been available. Verification of our results in another laboratory with the exclusion of several potentially pertinent variables is advisable.
Marklová
Eliska
E
Department of Pediatrics, Charles University in Prague, Faculty of Medicine and University Hospital, Hradec Králové, Czech Republic. marklova@lfhk.cuni.cz
Albahri
Ziad
Z
D000653:Amniotic Fluid / Q000378:metabolism*; D018981:Congenital Disorders of Glycosylation / Q000097:blood / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D005333:Fetus / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D020033:Protein Isoforms / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism; D000509:alpha-Fetoproteins / Q000378:metabolism*
D020033:Protein Isoforms; D014168:Transferrin; D000509:alpha-Fetoproteins