Congenital deficiency of AFP and Down syndrome screening

Sher, Carron; Shohat, Mordechai

doi:10.1002/(sici)1097-0223(199709)17:9<884::aid-pd163>3.0.co;2-n

Cited by 9 publications

(3 citation statements)

References 5 publications

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“…Mammalian AFP is a fetal tumor-associated (oncofetal) protein that first and foremost promotes growth in a variety of in vitro (cell) and in vivo (animal) models (6,7,269) (Table IX). The presence of AFP is known to be associated with the successful completion of term pregnancies in mammals, and even nanogram amounts have been reported in fetuses and newborns that were thought to lack serum AFP; hence, it appears that even minute amounts of AFP may still be necessary during human pregnancy (270,271). However, knockout mice for AFP have not yet been developed and the final answer must await the test of scientific endeavor.…”

Section: Update On Afp Physiology and Clinical Potentialmentioning

confidence: 99%

Alpha-fetoprotein Structure and Function: Relevance to Isoforms, Epitopes, and Conformational Variants

Mizejewski

2001

Exp Biol Med (Maywood)

247

205

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Mammalian alpha-fetoproteln (AFP) Is classified as a member of the albuminoid gene superfamily consisting of albumin, AFP, vitamin D (Gc) protein, and alpha-albumin. Molecular variants of AFP have long been reported In the biomedical literature. Early studies Identified Isoelectrlc pH isoforms and lectin-binding variants of AFP, which differed In their physicochemical properties, but not In amino acid composition. Genetic variants of AFP, differing in mRNA kllobase length, were later extensively described in rodent models during fetal/perinatal stages, carcinogenesis, and organ regeneration. With the advent of monoclonal antibodies in the early 1980s, multiple antigenic epitopes on native AFP were detected and categorized, culminating In the Identification of six to seven major epltopes. During this period, various AFP-blndlng proteins and receptors were reported to inhibit certain AFP Immunoreactlons. Concomlttantly, human and rodent AFP were cloned and the amino acid sequences of the translated proteins were divulged. Once the amino acid composition of the AFP molecule was known, enzymatic fragments could be identified and synthetic peptide segments synthesized. Following discovery of the molten globule form In 1981,the existence of transitory, intermediate forms of AFP were acknowledged and their physiological significance was realized. In the present review, the various Isoforms and variants of AFP are discussed In light of their potential biological relevance.

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Section: Update On Afp Physiology and Clinical Potentialmentioning

confidence: 99%

Alpha-fetoprotein Structure and Function: Relevance to Isoforms, Epitopes, and Conformational Variants

Mizejewski

2001

Exp Biol Med (Maywood)

247

205

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“…AFP is known to be associated with the successful completion of term pregnancies in mammals and even minute amounts of AFP may still be necessary during human pregnancy [13] . The capability of both up and down modulation of growth and differentiation as a dose-dependent function of AFP has been demonstrated in a multitude of cell types including placental, ovarian, uterine, lymphoid, epidermal, endothelial, testicular, breast, and liver [14][15][16][17][18] .…”

Section: Discussionmentioning

confidence: 99%

Expression and location of α-fetoprotein during rat colon development

Liu¹,

Dong²,

Sun³

et al. 2009

WJG

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AIM:To investigate the expression of a-fetoprotein (AFP), a cancer-associated fetal glycoprotein, and its involvement during rat colon development. METHODS:Colons from Sprague-Dawley rat fetuses, young and adult (8 wk old) animals were used in this study. Expression levels of AFP in colons of different development stage were detected by reversetranscriptase PCR (RT-PCR) and Western blotting. To identify the cell location of AFP in the developing rat colons, double-immunofluorescent staining was performed using antibodies to specific cell markers and AFP, respectively. RESULTS:The highest levels of AFP mRNA were detected in colons of rats at embryonic day 18.5 (e18.5). Compared to e18.5 d, the AFP expression was significantly decreased during rat development [85% for e20.5, P < 0.05, 58% for postnatal day 0.5 (P0.5), P < 0.05, 37% for P7, P < 0.05, 24% for P14, P < 0.05, and 11% for P21, P < 0.05] and undetected in adult rats.Only the 72-kDa isoform of AFP was detected by Western blotting, the expression pattern was similar to AFP mRNA and conformed to the results of mRNA expression. The AFP positive staining was identical to different distribution patterns in fetuses, young and adult animals and positive staining for both AFP and vimentin was overlapped in mesenchymal cells at each stage tested. CONCLUSION:This study has for the first time demonstrated that AFP is localized in the mesenchyme of rat colon from the embryo to the weaning stage by immunofluorescence and presents 72-kDa isoform in the developing rat colons by Western blotting. The dynamic expression of AFP in the various developmental stages of the colon indicates that AFP might be involved in many aspects of colon development.

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“…2 In such situations, the difficulty is to distinguish real low AFP values in patients at high risk of maternal or fetal abnormalities 7 from congenital absence of AFP. 3 Indeed, molecular defect in the AFP gene expression could conceal 1 of the 18 clinical manifestations observed in case of low levels of serum AFP. 7 In our case, these clinical manifestations have been excluded thanks to cytogenetic and biochemical investigations and to ultrasound examinations.…”

Section: Discussionmentioning

confidence: 99%

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

et al. 2008

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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 bhCG 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.

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Congenital deficiency of AFP and Down syndrome screening

Cited by 9 publications

References 5 publications

Alpha-fetoprotein Structure and Function: Relevance to Isoforms, Epitopes, and Conformational Variants

Alpha-fetoprotein Structure and Function: Relevance to Isoforms, Epitopes, and Conformational Variants

Expression and location of α-fetoprotein during rat colon development

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

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