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.

[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.

The anxiety caused by abnormal results of Down syndrome screening tests.

The objective of our survey was to evaluate the anxiety experienced by women receiving abnormal results of prenatal Down syndrome screening by an electronic anonymous survey. Anxiety level was evaluated by a six-item Spielberger State-Trait Anxiety Inventory. Of 559 respondents, high anxiety scores were reported in the majority (86.0%). Higher anxiety scores were noted in women informed of the abnormal result by the caregiver vs. written answer. 59.1% of the respondents preferred the risk reported as percentage, while only 4.4% gave precedence to the current form (e.g. 1 in 100). The participants noted several factors which could relieve their anxiety, including an explanatory booklet (72.4%) or a website (77.9%). In conclusion, women receiving abnormal results of Down syndrome screening experience significant anxiety. Efforts should be made to relieve this distress, including changing the historical ratio risk format to percentage, adding a non-directive verbal annotation, an explanatory website and improving health professionals' understanding of the exact statistical meaning of the risk.Impact statementWhat is already known on this subject? Abnormal results of prenatal screening for Down syndrome might cause the women significant anxiety. Several simple methods are able to relieve this distress; however, they are frequently not implemented in the routine practice.What the results of this study add? We show that abnormal results of the screening tests are associated with high anxiety scores in the majority of women (86.0%). The majority of the respondents preferred the risk reported as percentage (vs. historical representation as a ratio). The participants noted several factors which could relieve their anxiety, including an explanatory booklet or a website.What the implications are of these findings for clinical practice and/or further research? Based on the results, we discuss the numerous ways able to available alleviate the distress.

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.

The yield of chromosomal microarray in pregnancies with congenital cardiac defects and normal noninvasive prenatal screening.

BACKGROUND: Evidence comparing the yield of chromosomal microarray analysis to noninvasive prenatal screening in pregnancies with congenital heart anomalies is currently limited. OBJECTIVE: This study aimed to examine the residual risk of clinically significant chromosomal microarray analysis results in fetuses with congenital heart defects by its various subtypes following a normal noninvasive prenatal screening. STUDY DESIGN: Using a population-based, countrywide computerized database, we retrieved the reports of all pregnancies undergoing chromosomal microarray analysis because of congenital heart defects through the years 2013-2019. We examined the risk of clinically significant (pathogenic and likely pathogenic) chromosomal microarray analysis results and compared it with the results of a local cohort of low-risk pregnancies. Of 5541 fetuses, 78 (1.4%) showed abnormal results. The residual risk of abnormal chromosomal microarray analysis results was calculated using several options-trisomies 21, 18, and 13; sex chromosome aneuploidies; 22q11.2 deletion, and deletions and duplications of at least 10 MB in size (genome-wide noninvasive prenatal screening)-following the exclusion of theoretically detectable noninvasive prenatal screening anomalies. RESULTS: Of the 1728 fetuses with congenital heart defects, 93 (5.4%) showed clinically significant chromosomal microarray analysis results (relative risk, 2.7; 95% confidence interval, 2.3-3.1). The result of pregnancies with fetuses with congenital heart defects was compared with the results of the control population. Unique variants were found in 15 pregnancies (16.1%). The detection rate of noninvasive prenatal screening in isolated congenital heart defects varied from 1.0% (aimed at 3 common trisomies) to 2.2% (aimed at 5 common aneuploidies and 22q11.2 deletion) using noninvasive prenatal screening. In nonisolated congenital heart defects, the noninvasive prenatal screening detection rates ranged from 7.8% (aimed at common autosomal trisomies) to 9.2% using genome-wide noninvasive prenatal screening. The residual risk of clinically significant chromosomal microarray analysis results following normal noninvasive prenatal screening ranged from 2.0% to 2.8% in isolated congenital heart defects and 4.5% to 5.9% in nonisolated cases and was significantly higher than those of the control cohort in all noninvasive prenatal screening options. In addition, the residual risk following noninvasive prenatal screening aimed at chromosomes 13, 18, 21, X, and Y was significantly higher than those of the control cohort for most specific congenital heart defect subtypes, except for ventricular septal defects and aberrant right subclavian artery. CONCLUSION: The residual risk of clinically significant chromosomal microarray analysis results in pregnancies with fetuses with congenital heart defects following normal noninvasive prenatal screening was higher than those in pregnancies with normal ultrasound in most isolated and nonisolated congenital heart defect subtypes. This information should be taken into account by obstetricians and genetic counselors when considering the option of diagnostic testing.

The effect of polyhydramnios degree on chromosomal microarray results: a retrospective cohort analysis of 742 singleton pregnancies.

PURPOSE: To analyze the risk for clinically significant microarray aberrations in pregnancies with polyhydramnios. METHODS: Data from all chromosomal microarray analyses (CMA) performed due to polyhydramnios between January 2013 and December 2019 were retrospectively obtained from the Ministry of Health Database. The rate of clinically significant (pathogenic and likely pathogenic) CMA findings in isolated and non-isolated polyhydramnios cohorts was compared to a local control group of 5541 fetuses with normal ultrasound, in which 78 (1.4%) abnormal results were demonstrated. Subgroup analyses were performed by the degree of polyhydramnios, week of diagnosis, maternal age, and the presence of additional sonographic anomalies. RESULTS: In the isolated polyhydramnios cohort, 19/623 (3.1%) clinically significant CMA aberrations were noted, a significantly higher rate compared to the control population. However, the risk for abnormal CMA results in the 158 cases with mild polyhydramnios (AFI 25-29.9, or maximal vertical pocket 8-11.9 cm) did not significantly differ from pregnancies with normal ultrasound. Of 119 cases of non-isolated polyhydramnios (most frequently associated with cardiovascular (26.1%) and brain (15.1%) anomalies), 8 (6.7%) abnormal CMA findings were noted, mainly karyotype-detectable. CONCLUSION: Mild polyhydramnios was not associated with an increased rate of clinically significant microarray results, compared to pregnancies with normal ultrasound. An extensive anatomical sonographic survey should be performed in pregnancies with polyhydramnios, with consideration of fetal echocardiography.

Chromosomal microarray should be performed for cases of fetal short long bones detected prenatally.

PURPOSE: To investigate the prevalence of pathogenic and likely-pathogenic variants detected by chromosomal microarray analysis (CMA), among pregnancies with fetal short long bones diagnosed by ultrasound. METHODS: The study cohort was based on cases of chromosomal microarray analyses performed nationwide for the indication of short long bones. RESULTS: CMA was performed in 66 cases of short long bones. There were 4 cases with a pathogenic/likely pathogenic result (6%). The rate of chromosomal abnormalities was significantly higher compared to the background risk for copy number variations (CNVs) in pregnancies with no sonographic anomalies (P < 0.001). The yield of CMA in our cohort was significantly higher for both isolated and non-isolated cases, for cases in which the lowest estimated bone length percentile was above the 3rd percentile (below 5th percentile), and for cases diagnosed with short long bones after 22 weeks but not for cases diagnosed after 24 weeks. CONCLUSION: The yield of CMA in cases with short long bones (both isolated and non-isolated) is significantly higher than the background risk for chromosomal anomalies in pregnancies with no sonographic anomalies. This suggests that CMA should be offered in pregnancies with a diagnosis of fetal short long bones.

The Yield of Chromosomal Microarray in Pregnancies Complicated with Fetal Growth Restriction Can Be Predicted According to Clinical Parameters.

INTRODUCTION: We evaluated the yield of chromosomal microarray analysis in pregnancies complicated with fetal growth restriction (FGR) according to specific clinical parameters. METHODS: The study was based on national records from the Israeli Ministry of Health. Chromosomal microarray analyses of amniocenteses performed nationwide for the indication of FGR, from January 2016 to March 2018, were included. The CMA yield was compared to 2 cohorts that reported the background risk. RESULTS: Of 174 tests performed for the indication of FGR, there were 11 cases with a pathogenic/likely pathogenic result (6.3%). The yield of CMA was significantly higher in cases with major structural findings (29.4 vs. 3.4%, p = 0.001), compared to isolated FGR but not for minor structural findings (6.1 vs. 3.4%, p = 0.5). The rate of chromosomal aberrations was significantly higher for all cases with FGR, when compared to the background risk of a cohort of normal pregnancies (odds ratio [OR] 4.7, 95% CI 2.5-9 and OR 6.09, 95% CI 3.2-11.4) but not for isolated cases or cases diagnosed after 24 weeks of pregnancy. CONCLUSIONS: Chromosomal microarray analysis should be performed for all pregnancies complicated with FGR diagnosed before 24 weeks and for cases with major structural anomalies.

Spectrum of genes for inherited hearing loss in the Israeli Jewish population, including the novel human deafness gene ATOH1.

Mutations in more than 150 genes are responsible for inherited hearing loss, with thousands of different, severe causal alleles that vary among populations. The Israeli Jewish population includes communities of diverse geographic origins, revealing a wide range of deafness-associated variants and enabling clinical characterization of the associated phenotypes. Our goal was to identify the genetic causes of inherited hearing loss in this population, and to determine relationships among genotype, phenotype, and ethnicity. Genomic DNA samples from informative relatives of 88 multiplex families, all of self-identified Jewish ancestry, with either non-syndromic or syndromic hearing loss, were sequenced for known and candidate deafness genes using the HEar-Seq gene panel. The genetic causes of hearing loss were identified for 60% of the families. One gene was encountered for the first time in human hearing loss: ATOH1 (Atonal), a basic helix-loop-helix transcription factor responsible for autosomal dominant progressive hearing loss in a five-generation family. Our results show that genomic sequencing with a gene panel dedicated to hearing loss is effective for genetic diagnoses in a diverse population. Comprehensive sequencing enables well-informed genetic counseling and clinical management by medical geneticists, otolaryngologists, audiologists, and speech therapists and can be integrated into newborn screening for deafness.

Lower rates of neural tube defects in Israel following folic acid supplementation policy.

Neural tube defects (NTDs) are common and disabling congenital malformations that remain a public health challenge despite prevention efforts. In 2000, The Israeli Ministry of Health published recommendations on daily folic acid (FA) supplementation for women of reproductive age and established a national NTD registry. This study aims to evaluate the long-term impact of the FA supplementation policy on NTD rates in Israel and the need for further intervention. In this descriptive report, we present the rate of NTD-affected pregnancies recorded in the registry between 2000 and 2012, their subtype (anencephaly, spina bifida or other), outcome (live birth, stillbirth or pregnancy termination), ethnic group (Jewish, Bedouin and non-Bedouin Muslim) and years of maternal education. The final analysis included 2374 NTD cases reported between 2000 and 2012, compared with 1,668,073 live births. During this period NTD rates decreased from 20.3 to 11.2 cases per 10,000 live births, a 45% reduction. Reductions were seen in rates of spina bifida, anencephaly and encephalocele. NTD rates decreased in all pregnancy outcomes and in all ethnic groups, though rates among Bedouins remain high. Women with higher levels of education tended to have lower NTD rates, and were more prone to choose termination of an affected pregnancy. Following the institution of FA supplementation in Israel, a substantial reduction was seen in NTD rates. Nonetheless, Israeli NTD rates remain higher than in other developed countries. FA interventions should continue to be vigorously implemented, especially in vulnerable populations. The global success of mandatory fortification of grain strongly advocates its consideration in Israel.

Impact of a national genetic carrier-screening program for reproductive purposes.

INTRODUCTION: The Israeli population, encompassing 9 million citizens, is comprised of diverse communities. The Ministry of Health genetic screening program for reproductive purposes was introduced in 2013. This program is mainly aimed at severe incurable diseases with high rates of infant and childhood morbidity and/or mortality, with a carrier frequency of at least 1:60 and/or a disease frequency of 1 in 15 000 live births. In this paper, we present the results of the national genetic carrier-screening program implementation. MATERIAL AND METHODS: Data acquisition for this study was performed by retrospectively searching Ministry of Health database, which includes the reports of 18 genetic laboratories performing genetic screening tests. RESULTS: During 2015-2017, a total of 919 820 carrier-screening genetic tests were executed. The overall number rose by 14.9% over these years. For about two-thirds of the presented disorders, carrier frequency was within the expected range. A decrease of 57% was noted in the observed number of patients with spinal muscular atrophy born during 2014-2017, compared with the expected rate. Familial dysautonomia, Canavan and Tay-Sachs diseases yielded a very low prevalence. CONCLUSIONS: Our results highlight the impact of a national genetic carrier-screening program. Couples at risk of an affected fetus mostly choose to perform preconception or prenatal diagnosis and to act accordingly. Our country has several characteristics enabling us to achieve this success, including considerable rates of endogamy and consanguineous marriages, increased frequency of founder mutations, and high fertility rates. In addition, wide accessibility of the tests and good compliance of the population must be noted. Still, raising the awareness and continuing education of population and caregivers about the importance and efficiency of carrier screening remains an important issue. Finally, expanding the existing tests into a uniform, wide genetic panel seems to be the next goal.

What have we learned from 691 prenatal chromosomal microarrays for ventricular septal defects?

INTRODUCTION: Ventricular septal defect (VSD) represents the most common type of congenital cardiac anomaly, affecting more than 1 in 300 live births. The objective of this study was to examine the incidence and nature of abnormal chromosomal microarray analysis (CMA) results in a large cohort of pregnancies with VSD. MATERIAL AND METHODS: Data acquisition was performed through the Ministry of Health computerized database. All CMA results performed due to VSD during 2013-2017 were included. The rates of clinically significant CMA results of cases with isolated and non-isolated VSD were compared with two control populations-a systematic review of 9272 pregnancies and a local cohort of 5541 fetuses with normal ultrasound. RESULTS: Overall, 691 CMA analyses performed due to a sonographic indication of VSD were detected. Of 568 pregnancies with isolated VSD, eight (1.4%) clinically significant copy number variants were detected, a nonsignificant difference compared with low risk pregnancies. Of the 123 pregnancies with non-isolated VSDs, 18 (14.6%) clinically significant CMA results were detected, a considerably increased risk compared with control pregnancies. Karyotype-detectable anomalies constituted 12 of the 18 abnormal CMA results in non-isolated VSD group (66.7%), a significantly higher proportion compared with 2 of 8 (25%) in isolated VSD cohort. CONCLUSIONS: The outcomes of our study, representing the largest number of CMA results in pregnancies with VSD, suggest that the rate of abnormal CMA findings in isolated VSD does not differ from pregnancies with normal ultrasound. This observation is true for populations undergoing routine common trisomy screening tests and early sonographic evaluation, as well as widely available non-invasive prenatal screening. Conversely, CMA analysis yields a high detection rate in pregnancies with non-isolated VSD. Our results question the recommendation to perform invasive prenatal testing for CMA in pregnancies with isolated VSD.

The yield of chromosomal microarray testing for cases of abnormal fetal head circumference.

Objectives: Chromosomal microarray analysis (CMA) is the method of choice for genetic work-up in cases of fetal malformations. We assessed the detection rate of CMA in cases of abnormal fetal head circumference (HC). Methods: The study cohort was based on 81 cases of amniocenteses performed throughout Israel for the indication of microcephaly (53) or macrocephaly (28), from January 2015 through December 2018. We retrieved data regarding the clinical background, parental HCs and work-up during the pregnancy from genetic counseling summaries and from patients' medical records. Results: There was only one likely pathogenic CMA result (1.89%): a 400-kb microdeletion at 16p13.3 detected in a case of isolated microcephaly. No pathogenic results were found in the macrocephaly group. Most fetuses with microcephaly were female (87.8%), while the majority with macrocephaly were males (86.4%). Conclusions: The results imply that CMA analysis in pregnancies with microcephaly may carry a small yield compared to other indications. Regarding macrocephaly, our cohort was too small to draw conclusions. In light of the significant gender effect on the diagnosis of abnormal HC, standardization of fetal HC charts according to fetal gender may normalize cases that were categorized outside the normal range and may increase the yield of CMA for cases of abnormal HC.

Multigene panel testing in unselected Israeli breast cancer cases: mutational spectrum and use of BRCA1/2 mutation prediction algorithms.

BACKGROUND: Studies assessing the contribution of non-BRCA1/2 gene mutations to inherited breast cancer (BC) predisposition consistently reported low (up to 4%) yield. The current study aimed at assessing the spectrum of non-BRCA mutations in unselected Israeli BC cases and the utility of BRCAPRO and Penn II models, as tools for prediction of detecting non-BRCA1/2 mutations in Israeli BC patients who tested negative for the predominant Jewish BRCA1/2 mutations. METHODS: All consecutive Jewish Israeli BC patients at the Sheba Medical center who tested negative for the predominant BRCA1/2 mutations and elected to perform multigene panel testing were included. For each patient probability of BRCA mutation detection was calculated by the Penn II algorithm and the BRCAPRO tool. RESULTS: Overall, 144 cases were included (median age at diagnosis was 48, range 20-73 years); 48% were Ashkenazim. One patient harbored a non-founder BRCA1 mutation (c.5434C>G; p.P1812A). Pathogenic/likely pathogenic (P/LP) mutations in non-BRCA1/2 genes were detected in additional 14/144 patients, including CHEK2 (n = 5), RAD51D (n = 2), MSH6 (n = 2), and one each in ATM, RET, TP53, NBN, and BAP1. Using a cutoff of 15% probability of BRCA mutation detection, both models accurately predicted the observed carrier rate of non-BRCA mutations. CONCLUSIONS: In unselected Jewish Israeli BC patients, the rate of detecting non-founder BRCA1/2 mutations is low, with CHEK2 mutations detected in 3.4% of cases. BRCA1/2 mutation prediction models may be utilized for selecting patients eligible for further multigene panel testing after exclusion of predominant BRCA1/2 mutations.

Microarray findings in pregnancies with oligohydramnios - a retrospective cohort study and literature review.

Objective To explore the risk for abnormal chromosomal microarray analysis (CMA) findings in pregnancies with oligohydramnios. Methods Data from all CMA analyses performed due to oligohydramnios between 2013 and 2017 were retrospectively obtained from the Israeli Ministry of Health database. The rate of clinically significant (pathogenic and likely pathogenic) findings was compared to a local cohort of pregnancies with normal ultrasound, yielding a 1.4% rate of abnormal CMA results. In addition, a search was conducted through the PubMed database addressing the issue. Results Fifty CMA analyses were performed due to oligohydramnios. The 2% risk for clinically significant CMA finding in pregnancies with oligohydramnios did not differ from the control population of 5541 pregnancies with normal ultrasound - relative risk (RR) 1.4 [95% confidence interval (CI) 0.2-10.2]. Literature search yielded 394 titles, of which four relevant articles were selected, all using fetal karyotyping. Conclusion There is yet insufficient evidence to support invasive prenatal testing in pregnancies with isolated oligohydramnios.

Microarray analysis in pregnancies with isolated unilateral kidney agenesis.

BackgroundThe objective of our study was to examine the risk for submicroscopic chromosomal aberrations among fetuses with apparently isolated solitary kidney.MethodsData acquisition was performed retrospectively by searching Israeli Ministry of Health-computerized database. All cases having chromosomal microarray analysis (CMA), referred because of an indication of isolated unilateral kidney agenesis between January 2013 and September 2016, were included. Rate of clinically significant CMA findings in these pregnancies was compared to pregnancies with normal ultrasound, based on a systematic review encompassing 9,792 cases and local data of 5,541 pregnancies undergoing CMA because of maternal request.ResultsOf the 81 pregnancies with isolated solitary kidney, 2 (2.47%) loss-of-copy number variants compatible with well-described deletion syndromes were reported (16p11.2-16p12.2 and 22q11.21 microdeletion syndromes). In addition, one variant of unknown significance was demonstrated. The relative risk for pathogenic CMA findings among pregnancies with isolated unilateral renal agenesis was not significantly different compared with the control population.ConclusionCMA analysis in pregnancies with unilateral renal agenesis might still be useful, to the same degree as it can be in the general population.