Cell-based non-invasive prenatal testing for monogenic disorders: confirmation of unaffected fetuses following preimplantation genetic testing.

Purpose: Proof of concept of the use of cell-based non-invasive prenatal testing (cbNIPT) as an alternative to chorionic villus sampling (CVS) following preimplantation genetic testing for monogenic disorders (PGT-M).

Method: PGT-M was performed by combined testing of short tandem repeat (STR) markers and direct mutation detection, followed by transfer of an unaffected embryo. Patients who opted for follow-up of PGT-M by CVS had blood sampled, from which potential fetal extravillous throphoblast cells were isolated.

Cell-based noninvasive prenatal testing (cbNIPT) detects pathogenic copy number variations.

In two cases, cell-based noninvasive prenatal testing (cbNIPT) detected pathogenic copy number variations (CNVs) in the fetal genome. cbNIPT may potentially be an improved noninvasive alternative for the detection of smaller CNVs.

Genetic disruption of slc4a10 alters the capacity for cellular metabolism and vectorial ion transport in the choroid plexus epithelium.

Background: Genetic disruption of slc4a10, which encodes the sodium-dependent chloride/bicarbonate exchanger Ncbe, leads to a major decrease in Na-dependent HCO import into choroid plexus epithelial cells in mice and to a marked reduction in brain intraventricular fluid volume. This suggests that Ncbe functionally is a key element in vectorial Na transport and thereby for cerebrospinal fluid secretion in the choroid plexus. However, slc4a10 disruption results in severe changes in expression of Na,K-ATPase complexes and other major transport proteins, indicating that profound cellular changes accompany the genetic manipulation.

The choroid plexus sodium-bicarbonate cotransporter NBCe2 regulates mouse cerebrospinal fluid pH.

Key Points: Normal pH is crucial for proper functioning of the brain, and disorders increasing the level of CO in the blood lead to a decrease in brain pH. CO can easily cross the barriers of the brain and will activate chemoreceptors leading to an increased exhalation of CO . The low pH, however, is harmful and bases such as HCO are imported across the brain barriers in order to normalize brain pH.

The murine choroid plexus epithelium expresses the 2Cl/H exchanger ClC-7 and Na/H exchanger NHE6 in the luminal membrane domain.

The choroid plexus epithelium within the brain ventricles secretes the majority of the cerebrospinal fluid (CSF). The luminal Na-K-ATPase acts in concert with a host of other transport proteins to mediate efficient fluid secretion across the epithelium. The CSF contains little protein buffer, but the pH value seems nonetheless maintained within narrow limits, even when faced with acid-base challenges.

Choroid plexus epithelial cells express the adhesion protein P-cadherin at cell-cell contacts and syntaxin-4 in the luminal membrane domain.

The choroid plexus epithelial cells (CPECs) belong to a small group of polarized cells, where the Na-K-ATPase is expressed in the luminal membrane. The basic polarity of the cells is, therefore, still debated. We investigated the subcellular distribution of an array of proteins known to play fundamental roles either in establishing and maintaining basic cell polarity or in the polarized delivery and recycling of plasma membrane proteins.

Polarization of membrane associated proteins in the choroid plexus epithelium from normal and slc4a10 knockout mice.

The choroid plexus epithelium (CPE) has served as a model-epithelium for cell polarization and transport studies and plays a crucial role for cerebrospinal fluid (CSF) production. The normal luminal membrane expression of Na(+),K(+)-ATPase, aquaporin-1 and Na(+)/H(+) exchanger 1 in the choroid plexus is severely affected by deletion of the slc4a10 gene that encodes the bicarbonate transporting protein Ncbe/NBCn2. The causes for these deviations from normal epithelial polarization and redistribution following specific gene knockout are unknown, but may be significant for basic epithelial cell biology.