Clinical utility of expanded non-invasive prenatal screening compared with chromosomal microarray analysis in over 8000 pregnancies without major structural anomaly

OBJECTIVES

To evaluate the theoretical added value of two types of non-invasive prenatal screening (NIPS) expansions in pregnancies without major structural anomalies over the commonly used NIPS for chromosomes 13, 18, 21, X and Y (5-NIPS) and to compare them with the added value of chromosomal microarray analysis (CMA).

METHODS

This was a retrospective cohort study based on CMA results of all pregnancies with normal ultrasound (including pregnancies with soft markers and with abnormal maternal serum screening) that had undergone amniocentesis between January 2013 to February 2022 and were registered in the database of the Rabin Medical Center genetic laboratory. We calculated the theoretical yield of 5-NIPS and compared the added value of expanded 5-NIPS for common microdeletions (1p36.3-1p36.2, 4p16.3-4p16.2, 5p15.3-5p15.1, 15q11.2-15q13.1 and 22q11.2) and genome-wide NIPS (including variants > 5 Mb) with the added value of CMA in the overall cohort and in subgroups according to indication for invasive testing.

RESULTS

Among the 8605 examined pregnancies, 122 (1.4%) clinically significant CMA results were demonstrated. Of these, 44 (36.1%) were theoretically detectable on 5-NIPS, with the rates of 1.56% in 642 pregnancies with abnormal maternal serum screening, 0.63% in 318 pregnancies with soft markers, 0.62% in 4378 women with advanced maternal age (≥ 35 years) and 0.15% in 3267 women younger than 35 years. In addition to aneuploidies detectable on 5-NIPS, three (0.03%) cases detectable on 5-NIPS expanded for common microdeletions and nine (0.10%) cases detectable on genome-wide NIPS (excluding common microdeletions) were identified in the overall cohort. The added value of expanded NIPS tools over 5-NIPS was significantly lower compared with that of CMA, for the overall cohort and subgroups.

CONCLUSIONS

5-NIPS and even genome-wide NIPS would miss 63.9% and 54.1% of clinically significant CMA findings, respectively. The added value of 5-NIPS expanded to detect common microdeletions over 5-NIPS is about 0.035%, and the overall added value of genome-wide NIPS aimed at large CNVs is about 0.14%, both much lower compared with the added value of CMA (0.91%). These findings should assist healthcare practitioners in guiding couples towards informed decision-making regarding the choice between prenatal invasive testing and NIPS. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Individual and poly-substance use and condomless sex among HIV-uninfected adults reporting heterosexual sex in a multi-site cohort

BACKGROUND

We analyzed the association between substance use (SU) and condomless sex (CS) among HIV-negative adults reporting heterosexual sex in the Seek, Test, Treat, and Retain (STTR) consortium. We describe the impact of SU as well as person/partner and context-related factors on CS, identifying combinations of factors that indicate the highest likelihood of CS.

METHODS

We analyzed data from four US-based STTR studies to examine the effect of SU on CS using two SU exposures: 1) recent SU (within 3 months) and 2) SU before/during sex. Behavioral data were collected via 1:1 or self-administered computerized interviews. Adjusted individual-study, multivariable relative risk regression was used to examine the relationship between CS and SU. We also examined interactions with type of sex and partner HIV status. Pooled effect estimates were calculated using traditional fixed-effects meta-analysis. We analyzed data for recent SU (n = 6781; 82% men, median age = 33 years) and SU before/during sex (n = 2915; 69% men, median age = 40 years).

RESULTS

For both exposure classifications, any SU other than cannabis increased the likelihood of CS relative to non-SU (8-16%, p-values< 0.001). In the recent SU group, however, polysubstance use did not increase the likelihood of CS compared to single-substance use. Cannabis use did not increase the likelihood of CS, regardless of frequency of use. Type of sex was associated with CS; those reporting vaginal and anal sex had a higher likelihood of CS compared to vaginal sex only for both exposure classifications (18-21%, p < 0.001). Recent SU increased likelihood of CS among those reporting vaginal sex only (9-10%, p < 0.001); results were similar for those reporting vaginal and anal sex (5-8%, p < 0.01). SU before/during sex increased the likelihood of CS among those reporting vaginal sex only (20%; p < 0.001) and among those reporting vaginal and anal sex (7%; p = 0.002). Single- and poly-SU before/during sex increased the likelihood of CS for those with exclusively HIV-negative partners (7-8%, p ≤ 0.02), and for those reporting HIV-negative and HIV-status unknown partners (9-13%, p ≤ 0.03).

CONCLUSION

Except for cannabis, any SU increased the likelihood of CS. CS was associated with having perceived HIV-negative partners and with having had both anal/vaginal sex.

Cut-off value of nuchal translucency as indication for chromosomal microarray analysis

OBJECTIVES

An association between isolated, increased nuchal translucency thickness (NT) and pathogenic findings on chromosomal microarray analysis (CMA) has been reported. A recent meta-analysis reported that most studies use a NT cut-off value of 3.5 mm. However, considering NT distribution and the commonly accepted 5% false-positive rate in maternal serum screening, NT cut-off levels should be reconsidered. The aim of this study was to assess different NT cut-off levels as indication for CMA and to determine whether CMA should be recommended for mildly increased NT of 3.0-3.4 mm.

METHODS

This was a retrospective, multicenter study of singleton pregnancies with CMA results and either normal NT and no other finding or with increased NT as the only medical indication for CMA at the time of an invasive procedure (increased NT was considered an isolated finding in cases of advanced maternal age). Women with normal fetal NT who underwent CMA did so at their own request. A single laboratory performed all genetic analyses. Comparative genomic hybridization microarray analysis or single nucleotide polymorphism array technology was used for CMA. If combined first-trimester screening (NT and biochemistry) indicated increased risk for common aneuploidies, the case was excluded. NT was used to divide cases into three groups (≤ 2.9 mm, 3.0-3.4 mm and ≥ 3.5 mm) and their CMA results were compared.

RESULTS

CMA results were recorded in 1588 pregnancies, among which 770 fetuses had either normal NT with no other finding or isolated increased NT. Of these, 462 had NT ≤ 2.9 mm, 170 had NT of 3.0-3.4 mm and 138 had NT ≥ 3.5 mm. Pathogenic copy number variants were found in 1.7%, 6.5% and 13.8% of cases, respectively.

CONCLUSION

Our results suggest that CMA should be recommended when fetuses have isolated, mildly increased NT (3.0-3.4 mm). Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Chromosomal microarray analysis in fetuses with aberrant right subclavian artery

OBJECTIVE

To evaluate the association between aberrant right subclavian artery (ARSA), with or without additional risk factors for aneuploidy or ultrasound abnormality, and results of chromosomal microarray analysis (CMA).

METHODS

This was a multicenter study of fetuses diagnosed with ARSA that underwent genetic analysis by CMA, all samples being analyzed in the same laboratory. Clinical investigation included nuchal translucency measurement, first- and second-trimester maternal serum screening, early and late second-trimester fetal anatomy scans and fetal echocardiography. Comparative genomic hybridization microarray analysis or single-nucleotide polymorphism array technology was used for CMA of DNA samples obtained from amniotic fluid.

RESULTS

CMA results were available for 63 fetuses with ARSA. In 36 fetuses, ARSA was an isolated finding, and no pathogenic variant was found. Additional ultrasound findings and/or risk factors for aneuploidy were present in 27 fetuses, five of which had pathogenic CMA results. Of these five, trisomy 21 was detected in a fetus with echogenic intracardiac focus (EIF), 22q11 deletion was detected in a fetus with EIF and an increased risk of trisomy 21 of 1:230 from maternal serum screening, 22q11 duplication was detected in a fetus with hypoplastic right kidney and choroid plexus cyst and 22q11 deletion was detected in a fetus with right aortic arch and clubfoot. The fifth fetus had increased nuchal translucency thickness (4 mm) and a ventricular septal defect, and CMA identified both 22q11 deletion and 1q21 duplication.

CONCLUSIONS

In fetuses with isolated ARSA, an invasive procedure for CMA is not indicated. However, CMA is recommended when additional ultrasound abnormalities or risk factors for aneuploidy are observed. The chromosomal findings in four of the five cases with an abnormal CMA result in our study would not have been detected by standard fetal chromosomal testing. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Insulin increases H2O2-induced pancreatic beta cell death

Insulin resistance results, in part, from impaired insulin signaling in insulin target tissues. Consequently, increased levels of insulin are necessary to control plasma glucose levels. The effects of elevated insulin levels on pancreatic beta (β) cell function, however, are unclear. In this study, we investigated the possibility that insulin may influence survival of pancreatic β cells. Studies were conducted on RINm, RINm5F and Min-6 pancreatic β-cells. Cell death was induced by treatment with H(2)O(2), and was estimated by measurements of LDH levels, viability assay (Cell-Titer Blue), propidium iodide staining and FACS analysis, and mitochondrial membrane potential (JC-1). In addition, levels of cleaved caspase-3 and caspase activity were determined. Treatment with H(2)O(2) increased cell death; this effect was increased by simultaneous treatment of cells with insulin. Insulin treatment alone caused a slight increase in cell death. Inhibition of caspase-3 reduced the effect of insulin to increase H(2)O(2)-induced cell death. Insulin increased ROS production by pancreatic β cells and increased the effect of H(2)O(2). These effects were increased by inhibition of IR signaling, indicative of an effect independent of the IR cascade. We conclude that elevated levels of insulin may act to exacerbate cell death induced by H(2)O(2) and, perhaps, other inducers of apoptosis.

Conversion of T4 gene 46 mutant deoxyribonucleic acid into nonviable bacteriophage particles

The T4 amber mutant N130 in gene 46 produces, upon infection of a nonpermissive host, about 10 times more phage equivalent of deoxyribonucleic acid (DNA) than viable phage particles. Intracellular DNA is shorter than its mature phage counterpart and is converted into nonviable, light phage particles (287S) with about half of the normal DNA content, incapable either of adsorbing to or killing host bacteria. This DNA is highly unstable and breaks down, upon extraction, into subunits one-tenth the normal length of T4 DNA. Electron micrographs showed that the nonviable particles consist of normal-sized capsids of various degrees of fullness. Abnormal tail structures (naked cores with the sheaths missing) were also observed. Under conditions of arrested DNA synthesis, late messenger ribonucleic acid is produced, but some species are rare or missing, resulting in uneven transcription of the late genes. Our findings indicate that continuous DNA replication is necessary for normal transcription in T4.

Presence and possible mode of action of a proteinaceous gonadotropin-like growth regulating factor in plant systems

Antiserum to human chorionic gonadotropin (HCG) caused marked inhibition of adventitious rooting of Begonia semperflorens and Chrysanthemum morifolium stem cuttings. Immuno-absorption of crude protein extract from chrysanthemum foliage through a column of polymerized and unsolubilized HCG antibodies resulted in a significant reduction in adventitious root promoting activity of the extract. These results are discussed in the light of a hypothesis that an endogenous protein growth regulating substance which immunologically resembles HCG exists in plant systems. Further experimentation with HCG suggests that its mode of action is possibly via the regulation of peroxidase enzymatic control of auxin levels.

BACK-SCATTERING AND SELF-ABSORPTION OF β−-PARTICLES

The self-absorption of the β−-radiation from S35 and P32 has been studied in various compounds. The function derived by Gora and Hickey has been shown to fit the data. The back-scattering of the β−-radiation from P32 by various elements and compounds has been examined and a semiempirical treatment used to suggest an effective atomic number for back-scattering by compounds.