[THE RISK FOR CLINICALLY SIGNIFICANT COPY NUMBER VARIANTS IN PREGNANCIES WITH TWO SOFT MARKERS].

INTRODUCTION: Soft sonographic markers, such as an intracardiac echogenic focus, are demonstrated in one out of 150 live births and are associated with a slightly increased risk of trisomy 21 and 18. In the case of an isolated soft marker, the recommendation to perform invasive tests such as amniocentesis or placental cyst testing depends to a large extent on the results of biochemical first and second trimester maternal serum screening. In the case of two soft markers, the women are referred to genetic counseling, and invasive testing is funded by the Ministry of Health. OBJECTIVES: To estimate the risk for clinically significant copy number variants (CNVs) in pregnancies with two soft markers. METHODS: This retrospective cohort study included all prenatal microarray tests performed during 2013-2021, due to demonstration of two soft markers (namely: echogenic intracardiac foci, choroid plexus cyst, single umbilical artery and mild pyelectasis). The rates of clinically significant (pathogenic and likely pathogenic) microarray findings were compared to a previously published cohort of 7235 pregnancies with normal ultrasound, in which 87 (1.2%) abnormal CNVs were noted. RESULTS: Of the 150 pregnancies with two soft markers, two (1.3%) clinically significant CNVs were found. The rate of abnormal microarray findings did not differ from baseline risk in pregnancies with normal ultrasound - relative risk of 1.11 (95% confidence interval 0.28-4.40). CONCLUSIONS: The risk for abnormal microarray findings in pregnancies with two soft markers was not significantly increased in comparison to control group of pregnancies with normal sonography. DISCUSSION: These results undermine the current national policy of genetic counseling and Ministry of Health-funded invasive testing in pregnancies with a combination of two soft markers. These findings are important for additional countries with similar management, and may facilitate the genetic counseling and informed decision-making in such cases.

Lessons learned from the first national population-based genetic carrier-screening program for Duchenne muscular dystrophy.

PURPOSE: To summarize the results of first year implementation of pan-ethnic screening testing for Duchenne muscular dystrophy (DMD) and present the ensuing challenges. METHODS: Data acquisition for this study was performed by retrospective search of Ministry of Health registry for reports of all laboratories performing genetic screening tests. DMD testing was performed by multiplex ligation-dependent probe amplification technology. In case of single-exon deletion, sequencing of the specific exon was performed to rule out underlying single-nucleotide variant. RESULTS: Of overall 85,737 DMD tests, 82 clinically significant findings were noted (0.095%, or 1:1,046 women). In addition, 80 findings with uncertain clinical significance were detected (0.093%, or 1:1072), as well as 373 cases (0.4%, or 1:230) of single-exon deletions subsequently identified as false positives because of underlying single-nucleotide variant, mostly variants in exon 8 in North African Jewish population, and in exon 48 in Arab Muslim population. CONCLUSION: Interpretation of population-based DMD carrier screening is complex, occasionally requiring additional genetic testing methods and ethical considerations. Multicenter data registry, including ethnic origin and familial segregation in selected cases, is crucial for optimal definition of the results during genetic counseling and informed decisions regarding prenatal testing.

[MOH SCREENING FOR TBCD IN COCHIN JEWS: COLLABORATION BETWEEN MEDICAL, RESEARCH AND COMMUNITY MEMBERS IN ACHIEVING PUBLIC HEALTH GOALS].

INTRODUCTION: PEBAT (Progressive Encephalopathy, Early-Onset, with Brain Atrophy and Thin Corpus Callosum) is a rare disease characterized by a significant and progressive, neurological deficit. The disease has autosomal recessive etiology and is caused by bi-allelic variants in the gene TBCD (Tubulin-Specific Chaperone D). In 2017 the disease was diagnosed in two sisters from Jewish Cochin ethnicity (originating in Karela in south India) in Israel. Genetic testing for the girls revealed the homozygous TBCD variant c.1423G>A (p.Ala475Thr). This variant was reported simultaneously in another unrelated patient of Cochin origin.

[SUMMARY AND UPDATES IN THE FIELD OF GENETIC TESTING IN ISRAEL - AS OF 2022].

INTRODUCTION: Considerable progress has been observed in the field of genetic counseling and testing in Israel, including the availability and funding of services. The purpose of the article is to summarize the management and present the updates in the field of genetic testing in Israel, as of 2022. The progress in the field of pregnancy-related genetic testing includes an ancestry-based annually updated genetic screening, which has significantly reduced the incidence of several severe and common hereditary diseases. A comprehensive and uniform genetic screening test was submitted for approval by the next basket committee.

Community data-driven approach to identify pathogenic founder variants for pan-ethnic carrier screening panels.

BACKGROUND: The American College of Medical Genetics and Genomics (ACMG) recently published new tier-based carrier screening recommendations. While many pan-ethnic genetic disorders are well established, some genes carry pathogenic founder variants (PFVs) that are unique to specific ethnic groups. We aimed to demonstrate a community data-driven approach to creating a pan-ethnic carrier screening panel that meets the ACMG recommendations. METHODS: Exome sequencing data from 3061 Israeli individuals were analyzed. Machine learning determined ancestries. Frequencies of candidate pathogenic/likely pathogenic (P/LP) variants based on ClinVar and Franklin were calculated for each subpopulation based on the Franklin community platform and compared with existing screening panels. Candidate PFVs were manually curated through community members and the literature. RESULTS: The samples were automatically assigned to 13 ancestries. The largest number of samples was classified as Ashkenazi Jewish (n = 1011), followed by Muslim Arabs (n = 613). We detected one tier-2 and seven tier-3 variants that were not included in existing carrier screening panels for Ashkenazi Jewish or Muslim Arab ancestries. Five of these P/LP variants were supported by evidence from the Franklin community. Twenty additional variants were detected that are potentially pathogenic tier-2 or tier-3. CONCLUSIONS: The community data-driven and sharing approaches facilitate generating inclusive and equitable ethnically based carrier screening panels. This approach identified new PFVs missing from currently available panels and highlighted variants that may require reclassification.

A single center experience with publicly funded clinical exome sequencing for neurodevelopmental disorders or multiple congenital anomalies.

Exome sequencing (ES) is an important diagnostic tool for individuals with neurodevelopmental disorders (NDD) and/or multiple congenital anomalies (MCA). However, the cost of ES limits the test's accessibility for many patients. We evaluated the yield of publicly funded clinical ES, performed at a tertiary center in Israel, over a 3-year period (2018-2020). Probands presented with (1) moderate-to-profound global developmental delay (GDD)/intellectual disability (ID); or (2) mild GDD/ID with epilepsy or congenital anomaly; and/or (3) MCA. Subjects with normal chromosomal microarray analysis who met inclusion criteria were included, totaling 280 consecutive cases. Trio ES (proband and parents) was the default option. In 252 cases (90.0%), indication of NDD was noted. Most probands were males (62.9%), and their mean age at ES submission was 9.3 years (range 1 month to 51 years). Molecular diagnosis was reached in 109 probands (38.9%), mainly due to de novo variants (91/109, 83.5%). Disease-causing variants were identified in 92 genes, 15 of which were implicated in more than a single case. Male sex, families with multiple-affected members and premature birth were significantly associated with lower ES yield (p < 0.05). Other factors, including MCA and coexistence of epilepsy, autism spectrum disorder, microcephaly or abnormal brain magnetic resonance imaging findings, were not associated with the yield. To conclude, our findings support the utility of clinical ES in a real-world setting, as part of a publicly funded genetic workup for individuals with GDD/ID and/or MCA.

Colchicine treatment increases the risk for fetal chromosomal aberrations-an observational study and systematic literature review.

OBJECTIVES: To examine the risk for chromosomal aberrations in fetuses of colchicine-treated patients in a large cohort, and to perform a systematic literature review on the subject. METHODS: For the observational study, a retrospective search was performed through the Ministry of Health computerized database, for all invasive tests performed due to parental colchicine treatment over the years 2003-19. The rate of aberrant karyotypes in pregnancies exposed to colchicine was compared with a local cohort of 2752 normal pregnancies, yielding six (0.2%) karyotype-detectable findings. In addition, a systematic literature search was conducted for studies examining the rate of chromosomal aberrations in pregnancies exposed to colchicine. RESULTS: The study group consisted of 755 pregnancies karyotyped due to colchicine exposure. A marked decrease due to this indication was noted over the years (i.e. 67 cases in 2003 vs 8 in 2019). Five (0.66%) chromosomal aberrations were noted: 47,XXY; 45,X0; 47,XYY; and two fetuses with trisomy 21. This rate was significantly increased compared with the control population [relative risk 2.2 (95% CI: 1.1, 4.2)]. Literature search yielded four studies encompassing 740 pregnancies. The rate of chromosomal aberrations ranged from 'none' (in three studies) up to 1.5%. Quality assessment of the evidence was defined as 'low'. CONCLUSION: The results of our observational study support the concern that colchicine treatment is associated with increased risk for fetal chromosomal aberrations; however, the absolute risk is relatively low (one in 151 pregnancies). This information should be taken into account when considering invasive testing in such pregnancies.

Chromosomal Microarray Analysis Results From Pregnancies With Various Ultrasonographic Anomalies.

OBJECTIVE: To examine chromosomal microarray analysis results in pregnancies with various ultrasonographic anomalies and to characterize the copy number variants in diverse fetal phenotypes. METHODS: We retrospectively examined chromosomal microarray analyses of amniocenteses performed nationwide as a result of fetal ultrasonographic anomalies (structural defects, fetal growth restriction, and polyhydramnios) between January 2013 and September 2017. The rate of abnormal chromosomal microarray findings was compared between the different phenotypes and with a previously described control population of 15,225 pregnancies with normal ultrasonographic findings. RESULTS: Clinically significant chromosomal microarray aberrations were detected in 272 of 5,750 pregnancies (4.7%): 115 (2%) karyotype-detectable and 157 (2.7%) submicroscopic. Most commonly detected copy number variants were 22q11.21 deletions (0.4%) followed by 22q11.21 gain of copy number (0.2%). Specific copy number variants detected among pregnancies with abnormal ultrasonographic findings were up to 20-fold more prevalent compared with low-risk pregnancies. Some variants were associated with specific phenotypes (eg, 22q11.21 microdeletions with cardiovascular and 17q12 microdeletions with genitourinary defects). CONCLUSION: The rate of abnormal amniotic chromosomal microarray analysis results is twice that of karyotypic abnormalities in pregnancies with various abnormal ultrasonographic findings.

The limited effect of information on Israeli pregnant women at advanced maternal age who decide to undergo amniocentesis.

BACKGROUND: A primary goal of amniocentesis is the detection of trisomy 21 (Down syndrome- DS) in the fetus. This procedure involves a small risk of miscarriage. As the risk of DS increases with maternal age, screening tests (maternal serum triple test and others) and age are used to generate a risk assessment, and amniocentesis is offered to women with high risk. In Israel, amniocentesis is government funded for women of advanced maternal age (AMA, i.e., ≥35 years), even if their risk assessment is low. The purpose of this study was to explore the reasons AMA women undergo amniocentesis, their knowledge about risk estimates, and to evaluate whether their decision is informed. METHODS: Shortly after undergoing amniocentesis, 42 consecutive women without a medical indication for amniocentesis other than age, completed a questionnaire that assessed their knowledge and opinions regarding screening tests, pregnancy termination, amniocentesis risks and the factors that affected their decision. RESULTS: Women rarely deliberated before undergoing amniocentesis. One third of those who had the screening test did not wait for the results before undergoing amniocentesis. Only one third of those who received the screening results remembered their risk estimation before going ahead with amniocentesis. Almost half (41 %) cited "age" as their main reason for undergoing amniocentesis, though only 44 % of these women could recall their age related DS risk. Sixty percent estimated their DS risk as low or very low but still had amniocentesis. Most participants (74 %) stated that they would consider termination of the pregnancy if the fetus was diagnosed with an intellectual deficit. CONCLUSIONS: These results cast doubt on whether AMA women's decision to undergo amniocentesis is based on risk estimates, as women seem to disregard risk estimates, and sometimes not even wait for them when making the decision. The policy of funding amniocentesis solely on the basis of age may have led to the conception that being over 35 alone is sufficient reason to undergo amniocentesis. This finding should inform policy makers, as it raises questions about the link between public funding and the choices of individual women, and has implications for healthcare expenditures.

A Priori Attitudes Predict Amniocentesis Uptake in Women of Advanced Maternal Age: A Pilot Study.

Amniocentesis is an invasive procedure performed during pregnancy to determine, among other things, whether the fetus has Down syndrome. It is often preceded by screening, which gives a probabilistic risk assessment. Thus, ample information is conveyed to women with the goal to inform their decisions. This study examined the factors that predict amniocentesis uptake among pregnant women of advanced maternal age (older than 35 years old at the time of childbirth). Participants filled out a questionnaire regarding risk estimates, demographics, and attitudes on screening and pregnancy termination before their first genetic counseling appointment and were followed up to 24 weeks of gestation. Findings show that women's decisions are not always informed by screening results or having a medical indication. Psychological factors measured at the beginning of pregnancy: amniocentesis risk tolerance, pregnancy termination tolerance, and age risk perception affected amniocentesis uptake. Although most women thought that screening for Down syndrome risk would inform their decision, they later stated other reasons for screening, such as preparing for the possibility of a child with special needs. Findings suggest that women's decisions regarding amniocentesis are driven not only by medical factors, but also by a priori attitudes. The authors believe that these should be addressed in the dialogue on women's informed use of prenatal tests.

Factors that affect the decision to undergo amniocentesis in women with normal Down syndrome screening results: it is all about the age.

BACKGROUND: Risk for foetal Down syndrome (DS) increases as maternal age increases. Non-invasive screening (maternal serum triple test) for DS is routinely offered to pregnant women to provide risk estimates and suggest invasive amniocentesis for definitive pre-natal diagnosis to high-risk women. OBJECTIVE: We examined women's decision process with regard to pre-natal screening, and specifically, the degree to which they take into account triple serum screening results when considering whether or not to undergo amniocentesis. DESIGN: Semi-structured phone interviews were conducted to assess recall of DS screening results, understanding of risk estimates and their effect on women's decision whether to undergo amniocentesis. The study included 60 pregnant Israeli women (half younger than 35 and half advanced maternal age - AMA), with normal DS screening results and no known ultrasound abnormalities. RESULTS: Age appeared to determine the decision process. The vast majority of AMA women had amniocentesis, many of them before receiving their DS screening results. Most AMA participants knew that their risk estimate was 'normal', but still considered themselves at high risk due to their age. Procedure-related risk (miscarriage) and other factors only had a minor effect on their decision. A minority of younger women had amniocentesis. Younger women mentioned procedure-related risk and having normal screening results as the main factors affecting their decision not to have amniocentesis. CONCLUSION: Age 35 is an anchor for the pre-determination regarding performing or avoiding amniocentesis. AMA women mention 'age' as their main reason to have amniocentesis and considered it an independent risk factor.

Population-based screening for breast and ovarian cancer risk due to BRCA1 and BRCA2.

In the Ashkenazi Jewish (AJ) population of Israel, 11% of breast cancer and 40% of ovarian cancer are due to three inherited founder mutations in the cancer predisposition genes BRCA1 and BRCA2. For carriers of these mutations, risk-reducing salpingo-oophorectomy significantly reduces morbidity and mortality. Population screening for these mutations among AJ women may be justifiable if accurate estimates of cancer risk for mutation carriers can be obtained. We therefore undertook to determine risks of breast and ovarian cancer for BRCA1 and BRCA2 mutation carriers ascertained irrespective of personal or family history of cancer. Families harboring mutations in BRCA1 or BRCA2 were ascertained by identifying mutation carriers among healthy AJ males recruited from health screening centers and outpatient clinics. Female relatives of the carriers were then enrolled and genotyped. Among the female relatives with BRCA1 or BRCA2 mutations, cumulative risk of developing either breast or ovarian cancer by age 60 and 80, respectively, were 0.60 (± 0.07) and 0.83 (± 0.07) for BRCA1 carriers and 0.33 (± 0.09) and 0.76 (± 0.13) for BRCA2 carriers. Risks were higher in recent vs. earlier birth cohorts (P = 0.006). High cancer risks in BRCA1 or BRCA2 mutation carriers identified through healthy males provide an evidence base for initiating a general screening program in the AJ population. General screening would identify many carriers who are not evaluated by genetic testing based on family history criteria. Such a program could serve as a model to investigate implementation and outcomes of population screening for genetic predisposition to cancer in other populations.

BRCA genetic testing of individuals from families with low prevalence of cancer: experiences of carriers and implications for population screening.

PURPOSE: BRCA genes are associated with hereditary breast and ovarian cancers. Guidelines worldwide currently recommend BRCA genetic testing in asymptomatic individuals only if they belong to "high-risk" families. However, population screening for BRCA1/2 may be the logical next step in populations with a high prevalence of founder mutations, such as Ashkenazi Jews. This study aimed to explore (i) the impact of a positive BRCA genetic test result on individuals who have neither a personal history nor a familial history of cancer and (ii) their attitudes toward the concept of population screening. METHODS: Semistructured in-depth interviews were carried out with 14 Ashkenazi Jewish women who were asymptomatic BRCA carriers and who belonged to families with low prevalence of cancer. RESULTS: Three main findings emerged: (i) having no family history of cancer was a source of optimism but also confusion; (ii) engaging in intensified medical surveillance and undergoing preventive procedures was perceived as health-promoting but also tended to induce a sense of physical and psychological vulnerability; and (iii) there was overall support for BRCA population screening, with some reservations. CONCLUSION: Women belonging to low-cancer-prevalence families within a "high-risk" ethnic community view BRCA genetic testing positively despite the difficulties entailed, because it allows prevention or early detection of cancer. However, implementing a BRCA population screening program should be carried out with proper pre- and post-testing preparation and support for the individuals undergoing testing.

The best marker combination using the integrated screening test approach for detecting various chromosomal aneuploidies.

AIMS: To evaluate the cross-trimester multiple marker correlation and the minimum marker combination needed for detecting various chromosomal aneuploidies. MATERIALS AND METHODS: Parturient women with singleton pregnancies who underwent non-interventional sequential screening test and followed prospectively were recruited. They all underwent first trimester combined nuchal translucency (NT), pregnancy-associated plasma protein-A (PAPP-A), and free beta-human chorionic gonadotrophin (f-betahCG), followed by second trimester measurement of unconjugated estriol (uE3), human chorionic gonadotrophin (hCG) and alpha-fetoprotein (AFP). Pearson correlation was applied to compute any cross-trimester marker correlation and logistic regression analysis was used to determine the minimum marker combination for detecting various categories of chromosomal aneuploidies. RESULTS: The current study included 552 normal and 43 chromosomal-affected pregnancies (24 Down's syndrome [DS], 7 Turner's syndrome, 8 Edward's syndrome, 4 Klinefelter syndrome and 5 triploidy) for which the results of both the screening tests and the pregnancy outcome were available. In the normal cases, a significant correlation was found between f-betahCG and hCG (r=0.52), as well as between PAPP-A and uE3 (r=0.174). In DS pregnancies, the NT correlated with both hCG (r=0.45) and uE3 (r=-0.39). In Turner's syndrome, uE3 correlated both with PAPP-A (r=0.97) and f-betahCG (r=0.97). No other significant correlations were found. Furthermore, with the exception of f-betahCG and hCG in the unaffected cases, all other markers correlation appeared very weak. For detecting all the above categories of aneuploidies, the combination of NT, PAPP-A and uE3 and the maternal age background risk were found adequate, with a 74% detection rate (DR) for a 5% false positive rate (FPR). For DS only, the combination of maternal age-related background risk and the combination of NT, PAPP-A, hCG and AFP yielded a 79% DR for a 5% FPR. CONCLUSIONS: The current study agrees with a previous report that, overall, there is no strong correlation between first and second trimester markers. The extension of the integrated test for detecting various categories of common chromosomal aneuploidies using NT, PAPP-A and uE3 deserves further evaluation.

Are amniotic fluid alpha-fetoprotein levels influenced by the gender in twin pairs?

OBJECTIVES: To examine the assumption that amniotic fluid alpha-fetoprotein (AFAFP) levels are different in female and male twin fetuses. DESIGN: Amniotic fluid levels of AFP in pregnancies with female and male fetuses in gender-concordant and gender-discordant twins were compared. A t test of p < 0.05 was considered significant. MATERIAL AND METHODS: Between 1995 and 1999, 332 genetic amniocenteses on twin pregnancies were performed at Meir Hospital, Kfar Saba, and Rambam Hospital, Haifa, Israel. One hundred and sixty-six were concordant for gender (84 females and 82 males) while 166 pairs differed in their gender. The amniotic fluid AFP levels of each sac were measured using fluorescent immunoassay methods by an AutoDELFIA machine. RESULTS: The mean levels of AFAFP were lower in female twins compared to their male counterparts in same-gender twins (p = 0.07), although the difference was quite small. Nevertheless, there was no such difference between AFAFP of male versus female fetuses in gender-discordant twins. CONCLUSIONS: The levels of AFAFP were higher in the male twins of gender-concordant twins in comparison to female twins. No such difference was found between female versus male fetuses in gender-disconcordant twins.