Evidence of genetic underexpression in chorionic villi samples of euploid fetuses with increased nuchal translucency at 10-11 weeks' gestation.
OBJECTIVE
To retrospectively investigate whether the genetic profile from chorionic villous sampling (CVS) found in euploid fetuses with increased NT differs from matched controls.


METHODS
We employed cDNA microarray technology to characterize and compare the gene expression profile of chorionic villous tissues (which encompass the trophoblast and inner mesenchymal core) belonging to four singleton male fetuses with increased NT at 10-11 weeks' gestation. A pool of four normal chorionic villous tissues belonging to four respective fetuses, matched for gestational age and gender, was used as controls.


RESULTS
In euploid fetuses, we found several underexpressed genes, possibly involved in mechanisms associated with the abnormal NT thickness. All these genes are likely to belong to the mesenchymal core of the villus that originates from the extraembryonic mesoderm, and thus might be closely representative of the embryonic genetic profile. They include: (1) genes of embryonic development and differentiation such as Endothelin 3 (EDN3) and secreted frizzled-related protein 4 (SFRP4); (2) genes of the extracellular matrix (ECM) metabolism such as tissue inhibitor of metalloproteinase1 (TIMP1), and disintegrin-like and matrix metalloproteinase (MMP) (reprolysin type) with thrombospondin type 1 Motif or ADAMTS2, exostoses (multiple)-like 1 (EXTL1), heparan sulfate (HS) 6-O-sulfotransferase 1 or HS6ST1, fibronectin 1 (FN1) and Integrin Alpha 10 (ITGA10) involved in HS and proteoglycan bio-synthesis, ECM synthesis and cell-matrix adhesion; (3) genes involved in vessel formation and differentiation such as angiogenic factor (VG5Q), and in blood pressure control and muscle contraction, like Endothelin 3 or EDN3 and sarcolemma associated protein (SLMAP). Such lower expressions of the villous tissues might be related to an immature genetic profile of the embryo development as well as abnormal regulation of ECM bio-synthesis and/or improper vessel growth and blood pressure control. Also, the results partially support the theories proposed for NT enlargement such as altered composition of ECM and abnormal/delayed development of the circulatory system.


CONCLUSIONS
Abnormal extraembryonic genetic expression is found at 10-11 weeks' gestation in euploid fetuses with increased NT. If both extra- and intraembryonic mesoderms express the same genetic alterations, then microarray analyses on CVS could be used to screen several mesoderm-derivate anomalies.
Prenatal Medicine Unit, Embryology and Applied Biology, University of Bologna, Italy. antonio.farina@unibo.it
Antonio
A
Farina
Stefano
S
Volinia
Diego
D
Arcelli
Francesca
F
Francioso
Paola
P
Desanctis
Cinzia
C
Zucchini
Gianluigi
G
Pilu
Paolo
P
Carinci
Danila
D
Morano
M Carla
MC
Pittalis
Patrizio
P
Calderoni
Sonia
S
Vagnoni
Nicola
N
Rizzo
D016022:Case-Control Studies; D015193:Chorionic Villi Sampling / Q000379:methods*; D025063:Chromosome Disorders / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D005865:Gestational Age; D006801:Humans; D007621:Karyotyping; D008423:Maternal Age; D048208:Nuchal Translucency Measurement / Q000379:methods*; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D012189:Retrospective Studies