Maria Carla Pittalis

Cytogenetic follow-up of chromosomal mosaicism detected in first-trimester prenatal diagnosis

To contribute to the risk assessment of true fetal mosaicism after detection of a mosaic chromosomal anomaly in chorionic villus samples (CVS) in order to enable more effective counseling and pregnancy management.

Circulating mRNA for epidermal growth factor‐like domain 7 (EGFL7) in maternal blood and early intrauterine growth restriction. A preliminary analysis

To evaluate the alteration in epidermal growth factor‐like domain 7 (EGFL7) mRNA expression in maternal blood from pregnancies affected by early‐onset intrauterine growth restriction (IUGR) at 20–24 weeks.

Intravascular intrauterine transfusion for severe erythroblastosis fetalis using different techniques

Over a 3-year period, 44 ultrasound-guided intravascular transfusions were performed between 18 and 32 weeks on 15 patients with severe erythroblastosis fetalis due to Rh immunization. In 4 fetuses, the first transfusion was performed before 20 weeks, in 6 between 20 and 25 weeks and in the remaining 5 between 25 and 31 weeks. Eight of the 15 fetuses were hydropic at the time of referral. Five transfusions were done in the intrahepatic umbilical vein, 6 were simple transfusions via percutaneous umbilical cord puncture, and 33 were partial exchange. There were 4 intrauterine deaths before 26 weeks, despite successfully performed transfusions: 3 of these fetuses were severely hydropic, while in the remaining fetus hydrops had been reversed in utero. Following delivery by cesarean section at 32 weeks of gestation, 1 of the neonates developed respiratory distress syndrome and died 17 h after birth. The overall survival rate was 67% (10 of 15 cases): 4 of the 8 hydropic fetuses (50%) and 6 of the 7 nonhydropic fetuses (83%) were alive at birth and survived the perinatal period. Three of the 5 losses occurred among the first 4 cases, while in the last 11 cases the survival rate increased to 82% (9 of 11).

Persistence of a monosomic cell line in a fetus with mosaic trisomy 8

We report on a fetus presenting with an increased nuchal translucency, in which chorionic villus sampling led to the diagnosis of mosaic trisomy 8. Ultrasound scan performed at 15+6 weeks revealed bilateral cleft lip and palate, flat facial profile, and arrhinia. Pregnancy was terminated at 16+6; postmortem examination showed additional findings including hypospadias, bilateral renal dysplasia, and focal portal fibrosis of the liver. In order to confirm the presence of trisomy 8, FISH analysis was performed in abnormal renal and hepatic tissue, which, unexpectedly, showed a higher fraction of cells with only one fluorescent probe signal (43% and 23%, respectively), if compared with normal fetal liver and kidney (3–10%). This finding is consistent with the survival in this fetus of a monosomic cell line after mitotic non‐disjunction, which is in contrast with what is generally thought about mosaic trisomy genesis. We hypothesize that the possible persistence of the monosomic cell line, in addition to the variable distribution of aneuploid cells in the body tissues, could explain the high heterogeneity of mosaic trisomy 8 phenotype.

Structural chromosomal abnormalities detected during CVS analysis and their role in the prenatal ascertainment of cryptic subtelomeric rearrangements

Mosaic structural chromosomal abnormalities observed along the trophoblast‐mesenchyme‐fetal axis, although rare, pose a difficult problem for their prognostic interpretation in prenatal diagnosis. Additional issues are raised by the presence of mosaic imbalances of the same chromosome showing different sizes in the different tissues, that is, deletions and duplications in the cytotrophoblast and mesenchyme of chorionic villi (CV). Some of these cytogenetic rearrangements originate from the post‐zygotic breakage of a dicentric chromosome or of the product of its first anaphasic breakage. Selection of the most viable cell line may result in confined placental mosaicism of the most severe imbalance, favoring the presence of the cell lines with the mildest duplications or deletions in the fetal tissues. We document three cases of ambiguous results in CV analysis due to the presence of different cell lines involving structural rearrangements of the same chromosome which were represented differently in the trophoblast and the mesenchyme. Observation by conventional karyotype of a grossly rearranged chromosome in one of the CV preparations (direct or culture) was crucial to call attention to the involved chromosomal region in other tissues (villi or amniotic fluid), allowing the prenatal diagnosis through molecular cytogenetic methods of subtelomeric rearrangements [del(7)(q36qter); del(11)(q25qter); del(20)(p13pter)]. This would have surely been undiagnosed with the routine banding technique. In conclusion, the possibility to diagnose complex abnormalities leading to cryptic subtelomeric rearrangements, together with a better knowledge of the initial/intermediate products leading to the final abnormal cryptic deletion should be added to the advantages of the CV sampling technique.

Author's response to the letter by Basaran et al.

This letter by Basaran comments on our article about serum pregnancy associated plasma protein A (PAPPA) and serum alpha-fetoprotein (AFP) before and after chorionic villus sampling (CVS). The title of Basaran’s letter is misleading, as our paper does not affirm any reliable association between serum markers and preeclampsia (PE) but, instead, a rise in serum levels before and after CVS as a possible correlation with the degree of villus disruption. Of course, as villus disruption has been associated with PE, a correlation between the degree of marker aberration and PE might be possible, but that is not to say it is clearly demonstrated. Basaran’s letter contains several criticisms, basically addressing the results and the statistical method. However, the second part does not at all relate to our paper as it reports some analyses advanced by other studies about the risk of PE and CVS. I, thus, fail to grasp the real purpose of this letter, which seems no more than a cursory reanalysis of other studies. However, I am more than happy to clarify the items that regard our paper. One point of confusion may be that Basaran did not read the conclusion or the aim of our paper carefully. He focused on the following items:

Intrahepatic Cholestasis of Pregnancy: mRNAs for LIPF and ELOVL4 Genes Are Not Detectable in Circulating Maternal Plasma.

tions including preeclampsia [3] , intrauterine growth restriction [4] , placenta accreta [5] , congenital heart disease [6] , threatened abortion [7] and fetal genetic diseases [8] . The link between the fetus and the mother is represented by the apoptosis of placental and/or trophoblastic cells, which are considered the major source of circulating fetal genetic material. Recently, Wei et al. [9] demonstrated an aberrant gene profile in the placenta of women with ICP when compared to controls. Specifically, 293 variably expressed genes belonging to 20 functional categories that may be involved in the disease were identified, including a family of six genes involved in the lipid metabolism process: LPL (lipoprotein lipase), PLA2G4C (phospholipase A2, group IVC), ELOVL4 (elongation of very long chain fatty acids-like 4), APOD (apolipoprotein D), LIPF (lipase gastric) and DHCR7 (7-dehydrocholesterol reductase). Based on these results, we selected two genes out of six: lipase gastric (LIPF) which encodes an enzyme involved in the digestion of dietary triglycerides in the gastrointestinal tract, and fatty acid elongase 4 (ELOVL4), a member of the ELO family encoding a membrane-bound protein that Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder that typically appears during the second or third trimester of pregnancy. It is characterized by the onset of skin pruritus and elevated values in liver function tests in previously healthy pregnant women. ICP tends to resolve after delivery, but it has been associated with a high incidence of fetal complications such as preterm delivery, fetal distress and stillbirth. Its etiology is still unknown and no specific trigger factors, neither genetic nor environmental, have been identified [1] . However, altered lipid profiles have been well documented in ICP [2] , showing higher levels of low-density lipoprotein cholesterol, apolipoprotein B-100 and total cholesterol, and lower levels of high-density lipoprotein cholesterol. Furthermore, impaired canalicular transport of biliary solutes involving the ABCB4 (adenosine triphosphate-binding cassette) gene encoding the multidrug resistance 3 (MDR3) protein has been found, justifying the search for some specific MDR3 gene mutations in the diagnosis of ICP [1] . In the past, many circulating mRNA species have been studied as possible tools for the evaluation of some clinical condi-

P04.15: Prenatal detection of single umbilical artery: accuracy of ultrasound and prediction of outcome

and kyphosis of the thoracic spine was found. Dissection of the spine and costae confirmed the suspected butterfly vertebrae at the thoracic III-IV. segments, thoracic X. hemivertebra and absence of right costa X. There was no other abnormality by autopsy either. Spinal radiographs and autopsy findings confirmed the prenatal ultrasound diagnosis. In the second case in the newborn only isolated hemivertebra was detected. Conclusion: Our presented cases suggest that sonographically detected, isolated, abnormal spinal curvature, marked scoliosis, kyphosis and irregularities along the parallel line formed by the vertebral body ossification centres and/or the two posterior arch ossification centres on either side, make possible to detect spondylocostal dysostosis prenatally. Isolated hemivertebra might be associated with a favourable outcome.