A new mutation in the AFP gene responsible for a total absence of alpha feto-protein on second trimester maternal serum screening for Down syndrome
| Autor: | Philippe Labrune, Sophie Brisset, Clarisse Benattar, Marylise Hébert, Marie-Victoire Senat, Frédéric Parisot, Gérard Tachdjian, Olivier Picone, Liliane Capel, François Petit, Marie-Laure Maurin |
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| Rok vydání: | 2008 |
| Předmět: |
medicine.medical_specialty
Down syndrome Amniotic fluid Molecular Sequence Data Short Report Prenatal diagnosis Biology Pregnancy Prenatal Diagnosis Internal medicine Genetics medicine Humans Yolk sac Genetics (clinical) Fetus Base Sequence Albumin medicine.disease Blood proteins medicine.anatomical_structure Endocrinology Case-Control Studies Pregnancy Trimester Second Mutation embryonic structures Female alpha-Fetoproteins Down Syndrome Trisomy |
| Zdroj: | European Journal of Human Genetics. 17:387-390 |
| ISSN: | 1476-5438 1018-4813 |
| DOI: | 10.1038/ejhg.2008.186 |
| Popis: | Alpha feto-protein (AFP) is a major plasma protein produced by the yolk sac and the liver during the fetal period. During the second trimester of pregnancy, APF and betahCG serum concentrations are commonly used for screening Down syndrome. AFP deficiency is rare (estimated to be 1/105,000 newborns) and only one sequence alteration has previously been reported in the AFP gene. We report a new mutation in exon 5 of the AFP gene, leading to a total absence of AFP on 2nd-trimester maternal serum screening for Down syndrome, confirmed on the amniotic fluid. Despite this, fetal development and birth were normal. After PCR-amplification, the whole AFP gene was sequenced. The new mutation was a guanine to adenine transition in position 543 creating a premature stop codon in position 181. In order to search for eventual modifications of the amniotic fluid profile, proteins were separated by electrophoresis and compared with 10 normal amniotic fluids sampled at the same developmental age (18 weeks). In the amniotic fluid of our patient albumin rate was reduced whereas alpha1 and beta protein fractions were increased, suggesting that AFP deficiency may modify the distribution of protein fractions. This observation emphasizes the complex molecular mechanisms of compensation of serum protein deficiency. Studies on other families with AFP deficiency are necessary to confirm this observation. |
| Databáze: | OpenAIRE |
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