Exploring the factors affecting classification and reporting of uncertain prenatal microarray findings, using a "virtual fetus" model-a pilot study

OBJECTIVE

Significant discrepancy exists between laboratories in classification and reporting of copy number variants (CNVs). Studies exploring factors affecting prenatal CNV management are rare. Our "virtual fetus" pilot study examines these factors.

METHOD

Ten prenatally diagnosed CNVs of uncertain significance (VUS) > 1Mb, encompassing OMIM-morbid genes, inherited from healthy parents, were classified by 15 MD geneticists from laboratory, prenatal, and preimplantation genetic testing (PGT) units. Geneticists addressed factors affecting classification, obligation to report, and recommendation for invasive testing or PGT.

RESULTS

CNVs were classified likely benign (10.7%), VUS (74.7%), likely pathogenic (8.7%), or pathogenic (6.0%). Classification discrepancy was higher for losses versus gains. Classifying pathogenic/likely pathogenic was more common for losses (adjusted odds ratio [aOR] 10.9, 95% CI 1.55-76.9), and geneticists specializing in gynecology (aOR 4.9, 95% CI 1.03-23.3). 84.0% of respondents would report CNVs, depending on classification and family phenotype. Invasive testing in pregnancies was recommended for 29.3% of CNVs, depending on the classification and geneticist's specialization. PGT was recommended for 32.4%, depending on classification, experience years, and family's phenotype (38.0% for patients undergoing in vitro fertilization irrespectively, 26.7% otherwise).

CONCLUSION

Factors affecting CNV classification/reporting are mainly dosage, family phenotype, geneticist specialization and experience. Understanding factors from our pilot study may facilitate developing an algorithm for clinical consensus and optimal management.

Telemedicine Versus Traditional In-Person Consultations: Comparison of Patient Satisfaction Rates

Introduction: Data on patient satisfaction with the provision of genetic consultations using telemedicine are limited, especially those involving children. We compared patient satisfaction rates with telemedicine services versus traditional in-person encounters. Methods: A cross-sectional questionnaire-based study was conducted between January and June 2020. Questionnaires were distributed online to 1,672 consecutive patients who had received genetic counseling at our Genetics Institute in the clinical fields of adult and pediatric genetics, oncogenetics, and prenatal genetics, through in-person and/or telemedicine consultation. We used Likert scale with scores of 4-5 representing "satisfied"-"very satisfied" and 1-2 representing "very unsatisfied"-"unsatisfied." Results: The response rate was 27.3% (400 adults and 57 children <18 years), including 330 who had received in-person consultations (72.2%), 80 telemedicine consultations (17.5%), and 47 both consultations (10.3%). Mean satisfactory scores of 4-5 were reported by 82.1% in the in-person group versus 82.5% in the telemedicine group (p = 0.88). Mean scores of 1-2 were reported by 6.3% in the in-person group versus 11.2% in the telemedicine group (p = 0.31). No pediatric telemedicine group patient (n 12 = ) gave scores of 1-2 compared with 2/33 (6%) patients who had in-person pediatric consultations (p = 0.62). Most responders who had been counseled through telemedicine (n = 127, 84%) indicated willingness to use genetic services through telemedicine again. Conclusions: Users of genetic counseling through telemedicine, especially in the pediatric age group, were very satisfied at rates comparable to those of in-person consultations. Future research should evaluate patient compliance and views according to session type, information provided (e.g., diagnostic vs. negative results), and its nature (good vs. bad news).

The association between a carrier state of FMR1 premutation and numeric sex chromosome variations

PURPOSE

Women carriers of FMR1 premutation are at increased risk of early ovarian dysfunction and even premature ovarian insufficiency. The aim of this study was to examine a possible association between FMR1 permutation and numeric sex chromosome variations.

METHODS

A retrospective case-control study conducted in the reproductive center of a university-affiliated medical center. The primary outcome measure was the rate of sex chromosomal numerical aberrations, as demonstrated by haplotype analyses, in FMR1 premutation carriers compared to X-linked preimplantation genetic testing for monogenic/single gene defect (PGT-M) cycles for other indications that do not affect the ovarian follicles and oocytes.

RESULTS

A total of 2790 embryos with a final genetic analysis from 577 IVF PGT-M cycles were included in the final analysis. Mean age was similar between the groups, however, FMR1 carriers required more gonadotropins, and more women were poor responders with three or less oocytes collected. The ratio of embryos carrying a numeric sex chromosome variation was similar: 8.3% (138/1668) of embryos in the FMR1 group compared to 7.1% (80/1122) in the controls. A subgroup analysis based on age and response to stimulation has not demonstrated a significant difference either.

CONCLUSIONS

Although carriers of FMR1 premutation exhibit signs of reduced ovarian response, it does not seem to affect the rate of numeric sex chromosomal variation compared to women undergoing PGT-M for other indications. This suggests that the mechanism for chromosomal number aberrations in women at advanced maternal age are different to those FMR1 premutation carriers with poor ovarian reserve.

Exome sequencing as first-tier test for fetuses with severe central nervous system structural anomalies

OBJECTIVE

Prenatally detected central nervous system (CNS) anomalies present a diagnostic challenge. In this study, we compared the diagnostic yield of exome sequencing (ES) and chromosomal microarray analysis (CMA) in fetuses with a major CNS anomaly.

METHODS

This was a retrospective study of 114 cases referred for genetic evaluation following termination of pregnancy (TOP) due to a major CNS anomaly detected on prenatal ultrasound. All fetuses were first analyzed by CMA. All CMA-negative cases were offered ES. CMA-positive cases were reanalyzed using ES to assess its ability to detect copy-number variants (CNVs).

RESULTS

CMA identified a pathogenic or likely pathogenic (P/LP) CNV in 11/114 (10%) cases. Eighty-six CMA-negative cases were analyzed using ES, which detected P/LP sequence variants in 38/86 (44%). Among recurrent cases (i.e. cases with a previously affected pregnancy), the incidence of P/LP sequence variants was non-significantly higher compared with non-recurrent ones (12/19 (63%) vs 26/67 (39%); P = 0.06). Among the 38 cases with an ES diagnosis, 20 (53%) were inherited and carried a significant risk of recurrence. Reanalysis of 10 CMA-positive cases by ES demonstrated that the bioinformatics pipeline used for sequence variant analysis also detected all P/LP CNVs, as well as three previously known non-causative CNVs.

CONCLUSIONS

In our study, ES provided a high diagnostic yield (> 50%) in fetuses with severe CNS structural anomalies, which may have been partly due to the highly selected case series that included post-TOP cases from a specialist referral center. These data suggest that ES may be considered as a first-tier test for the prenatal diagnosis of major fetal CNS anomalies, detecting both P/LP sequence variants and CNVs. This is of particular importance given the time constraints of an ongoing pregnancy and the risk of recurrence in future pregnancies. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

NK-92 cells retain vitality and functionality when grown in standard cell culture conditions

NK-92 cells are an off-the-shelf, cell-based immunotherapy currently in clinical trials for a variety of cancer types. As the most 'NK-like' cell line available, it is also an important research tool. To date, NK-92 cells have been cultivated in a costly and time-consumingly prepared specialized medium, complicating research with these cells. Here we show that NK-92 cells grow in the comparatively user-friendly RPMI medium supplemented with IL-2. We demonstrate that their metabolic activity and replication rates are even improved in RPMI. Furthermore, they can be grown in cell culture dishes and do not need to be expanded in ventilated flasks. We show that in RPMI the cells retain functional characteristics relating to receptor expression, IFN-γ secretion, and killing. Our findings will enable more researchers to work with and manipulate this cell line, hopefully leading to further discoveries and improved therapies.

Improving renal phenotype and evolving extra-renal features of 17q12 deletion encompassing the HNF1B gene

BACKGROUND

HNF1B deletion/intragenic mutations are the most commonly identified genetic cause of congenital anomalies of the kidney and urinary tract (CAKUT) suggested by fetal ultrasound findings such as: parenchymal hyperechogenicity, overt cystic changes or gross morphological urinary system (UT) abnormalities. The postnatal evolution of these 17q12 deletions encompassing the HNF1B gene-associated findings has not been assessed in depth.

METHODS

In this observational study, we present postnatal follow-up findings in 5 of 6 cases (one pregnancy was terminated on parental request) of fetal-onset cystic/hyperechogenic kidneys eventually diagnosed with 17q12 microdeletion encompassing the HNF1B gene between 2009 and 2017.

RESULTS

Complete normalization of kidney parenchymal abnormalities and of depressed neonatal renal function was observed in 4/5 and 5/5 patients within 2-4.9 years and 1.5-8 months, respectively. All 5 patients had preserved normal renal function at 3-11 years of follow-up. The evolving later-onset renal features included: hypomagnesemia, hyperuricemia, urinary tract infection (UTI), and bilateral grade 3-4 vesicoureteral reflux and bladder diverticula in 3, 3, 2, and 1 patient, respectively. HNF1B gene deletion-associated extra-renal manifestations with delayed presentation were global developmental delay/autistic spectrum disorder (ASD), rolandic-type seizures, overweight, and borderline fasting hyperglycemia observed in 1-2 patients each. Family history was positive for small-size or asymptomatic cystic kidneys with normal function, diabetes mellitus, seizures, and mental/psychiatric problems in 3/6 cases.

CONCLUSIONS

Fetal-onset HNF1B deletion-associated kidneys' parenchymal abnormalities confirmed postnatally with initially depressed renal function might undergo complete resolution within several years and few months, respectively. However, later-onset urinary tract, metabolic, and neurodevelopmental features of this mutation might appear over years. Therefore, genetic molecular evaluation/diagnosis and continuous follow-up for evolving features are mandatory in affected children.

L1CAM variants cause two distinct imaging phenotypes on fetal MRI

Data on fetal MRI in L1 syndrome are scarce with relevant implications for parental counseling and surgical planning. We identified two fetal MR imaging patterns in 10 fetuses harboring L1CAM mutations: the first, observed in 9 fetuses was characterized by callosal anomalies, diencephalosynapsis, and a distinct brainstem malformation with diencephalic–mesencephalic junction dysplasia and brainstem kinking. Cerebellar vermis hypoplasia, aqueductal stenosis, obstructive hydrocephalus, and pontine hypoplasia were variably associated. The second pattern observed in one fetus was characterized by callosal dysgenesis, reduced white matter, and pontine hypoplasia. The identification of these features should alert clinicians to offer a prenatal L1CAM testing.

Familial Beckwith-Wiedemann syndrome: Prenatal manifestation and a possible expansion of the phenotype

We describe a case of Beckwith-Wiedemann syndrome (BWS) demonstrating pre- and post-natal intra-familial variability. Our first encounter with the family occurred in the 1990s following the birth of 3 affected offspring. The first two pregnancies presented with exomphalos and elevated second trimester maternal serum alpha-fetoprotein (msAFP, 3.43 and 4.01 MOM, respectively) as well as elevated maternal human chorionic gonadotrophin (mhCG, 4.33 and 8.8 MOM, respectively). The diagnosis of BWS was confirmed postnatally in both cases. The third ongoing pregnancy presented only with elevated mhCG (7.09 MOM) and no malformation. Nonetheless BWS was suspected. The diagnosis was confirmed postnatally with clinical manifestations including macroglossia and cleft palate. Two affected female siblings were also diagnosed with Mullerian agenesis in adulthood. Suspecting a common genetic etiology, sequencing of the CDKN1C gene revealed a maternally inherited, likely pathogenic variant (NM_000076.2: c.367_385del; p.(Ala123Serfs*143)) causative of BWS. Chromosomal microarray and whole exome sequencing did not reveal any other pathogenic variant that would explain the Mullerian agenesis. One of the affected females underwent successful preimplantation genetic testing (PGT) with a surrogate and gave birth to a healthy female. To the best of our knowledge, this is the first report of Mullerian agenesis as a possible rare expansion of the BWS phenotype. In addition, this case highlights the potential role of abnormal second trimester biochemical markers (msAFP, mHCG) as possible indicators of BWS, especially in familial cases.

Nectin4 is a novel TIGIT ligand which combines checkpoint inhibition and tumor specificity

BACKGROUND

The use of checkpoint inhibitors has revolutionized cancer therapy. Unfortunately, these therapies often cause immune-related adverse effects, largely due to a lack of tumor specificity.

METHODS

We stained human natural killer cells using fusion proteins composed of the extracellular portion of various tumor markers fused to the Fc portion of human IgG1, and identified Nectin4 as a novel TIGIT ligand. Next, we generated a novel Nectin4 blocking antibody and demonstrated its efficacy as a checkpoint inhibitor in killing assays and in vivo.

RESULTS

We identify Nectin4 to be a novel ligand of TIGIT. We showed that, as opposed to all other known TIGIT ligands, which bind also additional receptors, Nectin4 interacts only with TIGIT. We show that the TIGIT-Nectin4 interaction inhibits natural killer cell activity, a critical part of the innate immune response. Finally, we developed blocking Nectin4 antibodies and demonstrated that they enhance tumor killing in vitro and in vivo.

CONCLUSION

We discovered that Nectin4 is a novel ligand for TIGIT and demonstrated that specific antibodies against it enhance tumor cell killing in vitro and in vivo. Since Nectin4 is expressed almost exclusively on tumor cells, our Nectin4-blocking antibodies represent a combination of cancer specificity and immune checkpoint activity, which may prove more effective and safe for cancer immunotherapy.

Bypassing physiological puberty, a novel procedure of oocyte cryopreservation at age 7: a case report and review of the literature

OBJECTIVE

To report the first successful oocyte cryopreservation in a prepubertal girl.

DESIGN

Case report and review of the literature.

SETTING

Tertiary medical center.

PATIENT(S)

A 7-year-old prepubertal girl with Turner syndrome mosaicism (45,X[37]/47,XXX[15]) who underwent a novel fertility preservation procedure after fertility preservation counseling and informed decision of the parents.

INTERVENTION(S)

Controlled ovarian hyperstimulation with daily administration of 100 IU recombinant human follicle-stimulating and 50 IU recombinant human luteinizing hormone per milliliter, injection of 250 μg human chorionic gonadotropin was given 36 hours before the follicular aspiration procedure, and oocytes retrieved by a transabdominal ultrasound guided approach.

MAIN OUTCOME MEASURE(S)

Mature oocyte cryopreservation.

RESULT(S)

The first cryopreservation cycle with use of a gonadotropin-releasing hormone agonist trigger failed to yield oocytes. The second cycle with human chorionic gonadotropin trigger was successful. Six oocytes were retrieved, and all were mature metaphase 2. The patient was discharged in good condition with no complications.

CONCLUSION(S)

This novel procedure bypasses the timely physiologic progression of pubertal maturation of the hypothalamic-pituitary-ovarian axis to directly target the ovaries and achieve mature ovarian follicles. This innovative approach offers a new treatment modality for prepubertal girls who need fertility preservation such as in Turner syndrome or in cases that ovarian tissue cryopreservation is contraindicated.

A Unique Regulation Region in the 3' UTR of HLA-G with a Promising Potential

Human leukocyte antigen G (HLA-G) is a non-classical human leukocyte antigen (HLA) class I protein that interacts with inhibitory receptors and is commonly overexpressed in various cancers, thereby establishing itself as an inhibitory checkpoint immune ligand. It is also expressed in trophoblast cells during pregnancy and protects the fetus from immune rejection. Despite its crucial role and its intriguing expression pattern, the regulation of HLA-G’s expression is only partially understood. HLA-G’s mRNA is expressed in many tissues but the protein expression is restricted only to the cells mentioned above. Therefore, we suggest that HLA-G is post-transcriptionally regulated. Here, we reveal a distinctive site present only in the 3′ Untranslated region (UTR) of HLA-G, which might explain its unique expression pattern. Consequently, we attempted to find binding factors such as RNA binding proteins (RBPs) and microRNAS (miRs) that regulate HLA-G expression by interacting with this distinct site present in its 3′ UTR. Our research indicates that this site should be further studied in order to reveal its significance.

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.

Optimal timing for blastomere biopsy of 8-cell embryos for preimplantation genetic diagnosis

STUDY QUESTION

What is the optimal timing for blastomere biopsy during the 8-cell stage, at which embryos will have the best implantation potential?

SUMMARY ANSWER

Fast-cleaving embryos that are biopsied during the last quarter (Q4) of the 8-cell stage and are less affected by the biopsy procedure, and their implantation potential is better than that of embryos biopsied earlier during the 8-cell stage (Q1-Q3).

WHAT IS KNOWN ALREADY

Blastomer biopsy from cleavage-stage embryos is usually performed on the morning of Day 3 when the embryos are at the 6- to 8-cell stage and is still the preferred biopsy method for preimplantation genetic diagnosis (PGD) for monogentic disorders or chromosomal translocations. Human embryos usually remain at the 8-cell stage for a relatively long 'arrest phase' in which cells grow, duplicate their DNA and synthesize various proteins in preparation for the subsequent division.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort study. The study group (195 embryos) included all 8-cell stage embryos that underwent blastomere biopsy for PGD for monogenetic disorders and chromosomal translocations in our unit between 2012-2014 and cultured in the EmbryoScope until transfer. The control group (115 embryos) included all embryos that underwent intracytoplasmic sperm injection without a biopsy during the same period.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The 8-cell stage was divided into four quarters: the first 5 h post-t8 (Q1), 5-10 h post-t8 (Q2), 10-15 h post-t8 (Q3) and at 15-20 h post-t8 (Q4). Non-biopsied control embryos were divided into four equivalent quarters. Embryos were evaluated for timing of developmental events following biopsy including timing of first cleavge after biopsy, timing of comapction (tM) and start of blastulation (tSB). Timing of these events were compared between PGD and control embryos, as well as with 56 PGD implanted embryos with Known Implantation Data (PGD-KID-positive embryos).

MAIN RESULTS AND THE ROLE OF CHANCE

Embryos that were biopsied during Q3 (10-15 h from entry into 8-cell stage) were delayed in all three subsequent developmental events, including first cleavage after biopsy, compaction and start of blastulation. In contrast, these events occurred exactly at the same time as in the control group, in embryos that were biopsied during Q1, Q2 or Q4 of the 8-cell stage. The results show also that embryos that were biopsied during Q1, Q2 or Q3 of the 8-cell stage demonstrated a significant delay from the biopsied implanted embryos already in t8 as well as in tM and tSB. However, embryos that were biopsied during Q4 demonstrated dynamics similar to those of the biopsied implanted embryos in t8 and tM, and a delay was noticed only in the last stage of tSB.

LIMITATIONS, REASONS FOR CAUTION

This is a retrospective study that is limited to the timing of biopsy that is routinely performed in the IVF lab. A prospective study in which biopsy will be performed at a desired timing is needed in order to differ between the effect of biopsy itself and the cleavage rate of the embryo.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings showed that blastomere biopsy can be less harmful to further development if it is carried out during a critical period of embryonic growth, i.e during Q4 of the 8-cell stage. They also demonstrated the added value of time-lapse microscopy for determining the optimal timing for blastomere biopsy.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the routine budget of our IVF unit.

TRIAL REGISTRATION NUMBER

N/A.

IFNG-AS1 Enhances Interferon Gamma Production in Human Natural Killer Cells

Long, non-coding RNAs (lncRNAs) are involved in the regulation of many cellular processes. The lncRNA IFNG-AS1 was found to strongly influence the responses to several pathogens in mice by increasing interferon gamma (IFNγ) secretion. Studies have looked at IFNG-AS1 in T cells, yet IFNG-AS1 function in natural killer cells (NKs), an important source of IFNγ, remains unknown. Here, we show a previously undescribed sequence of IFNG-AS1 and report that it may be more abundant in cells than previously thought. Using primary human NKs and an NK line with IFNG-AS1 overexpression, we show that IFNG-AS1 is quickly induced upon NK cell activation, and that IFNG-AS1 overexpression leads to increased IFNγ secretion. Taken together, our work expands IFNG-AS1's activity to the innate arm of the type I immune response, helping to explain its notable effect in animal models of disease.

•

Natural killer cells (NKs) express a previously undescribed transcript of IFNG-AS1

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Upon activation, NKs upregulate IFNG-AS1 along with later IFNγ expression

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Overexpression of IFNG-AS1 in an NK line augments IFNγ expression and secretion

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IFNG-AS1 influences innate immunity, suggesting a general role in the IFNγ response

Fragile X Syndrome: Introduction

Fragile X syndrome (FXS) is one of the most common reasons for intellectual disability (ID). First described in the 1940s, it took many years to understand the disease. The awe-inspiring breakthroughs in both science and technology facilitated the recognition of the unique inheritance pattern and the genetic mechanism of fragile X. In this chapter we describe the history and evolution of our understanding of FXS as mirrored by advances in genetics.

Time-lapse imaging reveals delayed development of embryos carrying unbalanced chromosomal translocations

PURPOSE

The purpose of the study was to compare the morphokinetic parameters of embryos carrying balanced chromosomal translocations with those carrying unbalanced chromosomal translocations using time-lapse microscopy.

METHODS

The study group included 270 embryos that underwent biopsies on day 3 for preimplantation genetic diagnosis (PGD) for chromosomal translocations in our unit between 2013 and 2015. All embryos were incubated under time-lapse microscopy and evaluated for timing of developmental events up to day 5. The timing of these events was compared between balanced and unbalanced embryos, potentially viable and nonviable variants, and maternal versus paternal inheritance of the translocation.

RESULTS

The PGD analysis found that 209 (77%) of the 270 biopsied embryos carried an unbalanced translocation. Embryos carrying unbalanced translocations, which are expected to lead to implantation failure or miscarriage, cleaved less synchronously and were delayed in time of cleavage to the 4-cell stage (t4) and in time of start of blastulation (tSB) compared with balanced embryos (P < 0.05). Furthermore, embryos carrying nonviable translocations demonstrated a significant delay at the time of pronuclei fading (tPNf) compared with those carrying potentially viable translocations (P < 0.05). Embryos whose unbalanced translocations were of maternal origin were significantly delayed in most of the morphokinetic parameters (including tPNf, t2, t3, t4, t6, t7, t8, cc2, s2, and tSB) compared with embryos carrying balanced translocations (P < 0.05).

CONCLUSIONS

Embryos carrying unbalanced chromosomal translocations mainly of maternal origin undergo delayed development and asynchronous cleavage that may lead to implantation failure or miscarriage.

Whole-exome sequencing in fetuses with central nervous system abnormalities

OBJECTIVE

We describe our experience with whole-exome sequencing (WES) in fetuses with central nervous system (CNS) abnormalities following a normal chromosomal microarray result.

METHODS

During the study period (2014-2017) 7 cases (9 fetuses) with prenatally diagnosed CNS abnormality, whose chromosomal microarray analysis was negative, were offered whole-exome sequencing analysis.

RESULTS

A pathogenic or a likely pathogenic variant was found in 5 cases including a previously described, likely pathogenic de novo TUBA1A variant (Case #1); a previously described homozygous VRK1 variant (Case #2); an X-linked ARX variant (Case #3); a likely pathogenic heterozygous variant in the TUBB3 gene (Case #5). Finally, in two fetuses of the same couple (Case #6), a compound heterozygous state was detected, consisting of the NPHP1 gene deletion and a sequence variant of uncertain significance. Two additional cases had normal WES results.

CONCLUSION

Whole-exome sequencing may improve prenatal diagnosis in fetuses with CNS abnormalities.

Dilemmas in genetic counseling for low-penetrance neuro-susceptibility loci detected on prenatal chromosomal microarray analysis

BACKGROUND

Chromosomal microarray analysis is standard of care in fetuses with malformations, detecting clinically significant copy number variants in 5-7% of cases over conventional karyotyping. However, it also detects variants of uncertain significance in 1.6-4.2% of the cases, some of which are low-penetrance neuro-susceptibility loci. The interpretation of these variants in pregnancy is particularly challenging because the significance is often unclear and the clinical implications may be difficult to predict.

OBJECTIVE

The purpose of this study was to describe counseling dilemmas regarding low-penetrance neuro-susceptibility loci that are detected by prenatal chromosomal microarray analysis.

STUDY DESIGN

During the study period (January 2014 to December 2015), 700 prenatal chromosomal microarray analyses were performed. Cases were categorized as "indicated" (n=375) if there were abnormal sonographic findings or suggestive medical history and "patient choice" (n=325) in the presence of a structurally normal fetus with no other particular indication. The laboratory reported on copy number variants ≥400 Kb in size in loci known to be associated with genetic syndromes and ≥1 Mb in other areas of genome. Results were classified as gross aneuploidy, copy number variants, and normal. Copy number variants were categorized according to the American College of Medical Genetics standards and guidelines: pathogenic, variants of uncertain significance, or benign. Variants of uncertain significance were further subdivided into categories of likely pathogenic, variants of uncertain significance with no subclassification, and likely benign. Statistical analysis was performed with the use of Chi square test and Fisher's exact test to compare intergroup differences in incidence of the different result categories and demographic data.

RESULTS

Patient choice cases became more prevalent with time (35.5% in the beginning of the study, compared with 48.4% at the end of the study period). Clinically significant copy number variants were found in 14 of 375 (3.7%) of indicated cases vs only 2 of 325 (0.6%) of patient choice cases (P=.009). All "likely benign" variants consisted of low-penetrance neuro-susceptibility loci. The incidence thereof was similar between the indicated and patient choice groups (3.7% vs 3.4%; P=.85). In the indicated group, some variants of uncertain significance may have contributed to the abnormal anatomic findings. Conversely, in the patient choice group, the finding of low-penetrance neuro-susceptibility loci was often unexpected and confounding for prospective parents.

CONCLUSION

Prenatal chromosomal microarray analysis added clinically significant information in both groups. However, it also detected low-penetrance neuro-susceptibility loci in approximately 3.5% of the cases. This fact should be conveyed during pretest counseling to allow patients to make informed choices, particularly when chromosomal microarray is to be performed for patient choice.

Identification of novel microRNAs regulating HLA-G expression and investigating their clinical relevance in renal cell carcinoma

The non-classical human leukocyte antigen G (HLA-G) is expressed at a high frequency in renal cell carcinoma (RCC) and is associated with a higher tumor grade and a poor clinical outcome. This might be caused by the HLA-G-mediated inhibition of the cytotoxicity of T and NK cells. Therefore a selective targeting of HLA-G might represent a powerful strategy to enhance the immunogenicity of RCC lesions. Recent studies identified a number of HLA-G-regulating microRNAs (miRs) and demonstrated an inverse expression of some of these miRs with HLA-G in RCC in vitro and in vivo. However, it was postulated that further miRs might exist contributing to the tightly controlled selective HLA-G expression.By application of a miR enrichment assay (miTRAP) in combination with in silico profiling two novel HLA-G-regulatory miRs, miR-548q and miR-628-5p, were identified. Direct interactions of both miRs with the 3' untranslated region of HLA-G were confirmed with luciferase reporter gene assays. In addition, qPCR analyses and immunohistochemical staining revealed an inverse, expression of miR-628-5p, but not of miR-548q to the HLA-G protein in primary RCC lesions and cell lines. Stable overexpression of miR-548q and miR-628-5p caused a downregulation of HLA-G mRNA and protein. This leads in case of miR-548q to an enhanced NK cell-mediated HLA-G-dependent cytotoxicity, which could be reverted by ILT2 blockade suggesting a control of the immune effector cell activity at least by this miR. The identification of two novel HLA-G-regulatory miRs extends the number of HLA-G-relevant miRs tuning the HLA-G expression and might serve as future therapeutic targets.

Diagnostic utility of brain activity flow patterns analysis in attention deficit hyperactivity disorder

BACKGROUND

A previous small study suggested that Brain Network Activation (BNA), a novel ERP-based brain network analysis, may have diagnostic utility in attention deficit hyperactivity disorder (ADHD). In this study we examined the diagnostic capability of a new advanced version of the BNA methodology on a larger population of adults with and without ADHD.

METHOD

Subjects were unmedicated right-handed 18- to 55-year-old adults of both sexes with and without a DSM-IV diagnosis of ADHD. We collected EEG while the subjects were performing a response inhibition task (Go/NoGo) and then applied a spatio-temporal Brain Network Activation (BNA) analysis of the EEG data. This analysis produced a display of qualitative measures of brain states (BNA scores) providing information on cortical connectivity. This complex set of scores was then fed into a machine learning algorithm.

RESULTS

The BNA analysis of the EEG data recorded during the Go/NoGo task demonstrated a high discriminative capacity between ADHD patients and controls (AUC = 0.92, specificity = 0.95, sensitivity = 0.86 for the Go condition; AUC = 0.84, specificity = 0.91, sensitivity = 0.76 for the NoGo condition).

CONCLUSIONS

BNA methodology can help differentiate between ADHD and healthy controls based on functional brain connectivity. The data support the utility of the tool to augment clinical examinations by objective evaluation of electrophysiological changes associated with ADHD. Results also support a network-based approach to the study of ADHD.

Improving preimplantation genetic diagnosis (PGD) reliability by selection of sperm donor with the most informative haplotype

BACKGROUND

The study is aimed to describe a novel strategy that increases the accuracy and reliability of PGD in patients using sperm donation by pre-selecting the donor whose haplotype does not overlap the carrier's one.

METHODS

A panel of 4-9 informative polymorphic markers, flanking the mutation in carriers of autosomal dominant/X-linked disorders, was tested in DNA of sperm donors before PGD. Whenever the lengths of donors' repeats overlapped those of the women, additional donors' DNA samples were analyzed. The donor that demonstrated the minimal overlapping with the patient was selected for IVF.

RESULTS

In 8 out of 17 carriers the markers of the initially chosen donors overlapped the patients' alleles and 2-8 additional sperm donors for each patient were haplotyped. The selection of additional sperm donors increased the number of informative markers and reduced misdiagnosis risk from 6.00% ± 7.48 to 0.48% ±0.68. The PGD results were confirmed and no misdiagnosis was detected.

CONCLUSIONS

Our study demonstrates that pre-selecting a sperm donor whose haplotype has minimal overlapping with the female's haplotype, is critical for reducing the misdiagnosis risk and ensuring a reliable PGD. This strategy may contribute to prevent the transmission of affected IVF-PGD embryos using a simple and economical procedure.

TRIAL REGISTRATION

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. DNA testing of donors was approved by the institutional Helsinki committee (registration number 319-08TLV, 2008). The present study was approved by the institutional Helsinki committee (registration number 0385-13TLV, 2013).

Preliminary investigation of Brain Network Activation (BNA) and its clinical utility in sport-related concussion

Background: The clinical diagnosis and management of patients with sport-related concussion is largely dependent on subjectively reported symptoms, clinical examinations, cognitive, balance, vestibular and oculomotor testing. Consequently, there is an unmet need for objective assessment tools that can identify the injury from a physiological perspective and add an important layer of information to the clinician’s decision-making process.

Objective: The goal of the study was to evaluate the clinical utility of the EEG-based tool named Brain Network Activation (BNA) as a longitudinal assessment method of brain function in the management of young athletes with concussion.

Methods: Athletes with concussion (n = 86) and age-matched controls (n = 81) were evaluated at four time points with symptom questionnaires and BNA. BNA scores were calculated by comparing functional networks to a previously defined normative reference brain network model to the same cognitive task.

Results: Subjects above 16 years of age exhibited a significant decrease in BNA scores immediately following injury, as well as notable changes in functional network activity, relative to the controls. Three representative case studies of the tested population are discussed in detail, to demonstrate the clinical utility of BNA.

Conclusion: The data support the utility of BNA to augment clinical examinations, symptoms and additional tests by providing an effective method for evaluating objective electrophysiological changes associated with sport-related concussions.

Does the number of previous miscarriages influence the incidence of chromosomal aberrations in spontaneous pregnancy loss?

OBJECTIVE

Chromosomal aberrations are a common cause for miscarriage. The purpose of this study was to evaluate factors that influence the frequency of chromosomal abnormalities in miscarriages and provide clinicians with a guideline for management of such cases.

METHODS

The study included 170 women who experienced pregnancy loss between the 2004 and 2014. Cytogenetic analysis of products of conception (POC) was routinely performed.

RESULTS

Successful cytogenetic analysis was achieved in 144 cases (84%). Of these, 78 cases (54%) had a chromosomal aberration. The incidence of chromosomal aberrations was not statistically significant among patients with 1, 2, 3, 4 or ≥5 previous miscarriages (33.3%, 57.4%, 48.6%, 65.2%, and 59.1%, respectively, p = 0.227). The F/M ratio was similar in normal and abnormal POC karyotypes (1.2:1 and 1.3:1, respectively, p = 0.7).

CONCLUSION

Contrary to previous assumptions we did not find correlation between number of previous spontaneous miscarriages a women experienced and chromosomal aberration in her current miscarriage.

Blastomere biopsy for PGD delays embryo compaction and blastulation: a time-lapse microscopic analysis

PURPOSE

The purpose of the study was to explore the effect of blastomere biopsy for preimplantation genetic diagnosis (PGD) on the embryos' dynamics, further cleavage, development, and implantation.

METHODS

The study group included 366 embryos from all PGD treatments (September 2012 to June 2014) cultured in the EmbryoScope™ time-lapse monitoring system. The control group included all intracytoplasmic sperm injection (ICSI) embryos cultured in EmbryoScope™ until day 5 during the same time period (385 embryos). Time points of key embryonic events were analyzed with an EmbryoViewer™.

RESULTS

Most (88 %) of the embryos were biopsied at ≥8 cells. These results summarize the further dynamic development of the largest cohort of biopsied embryos and demonstrate that blastomere biopsy of cleavage-stage embryos significantly delayed compaction and blastulation compared to the control non-biopsied embryos. This delay in preimplanation developmental events also affected postimplantation development as observed when the dynamics of non-implanted embryos (known implantation data (KID) negative) were compared to those of implanted embryos (KID positive).

CONCLUSION

Analysis of morphokinetic parameters enabled us to explore how blastomere biopsy interferes with the dynamic sequence of developmental events. Our results show that biopsy delays the compaction and the blastulation of the embryos, leading to a decrease in implantation.

HNRNPR Regulates the Expression of Classical and Nonclassical MHC Class I Proteins

MHC class I molecules, in addition to their role in specific activation of the CTL of adaptive immune system, function also as the main ligands for NK cell inhibitory receptors, which prevent NK cells from killing normal, healthy cells. MHC class I proteins are divided into classical and nonclassical proteins. The former group consists of hundreds of HLA-A, B, and C alleles, which are universally expressed, whereas several alleles of the latter group, such as HLA-G, manifest a restricted expression pattern. Despite the important role played by these molecules in innate and adaptive immune responses, their complex expression regulation is not fully known. In our study, we investigated the regulation processes controlling the expression of MHC class I molecules, with a particular focus on their 3' untranslated regions. We identified heterogeneous nuclear ribonucleoprotein R (HNRNPR) as an important positive regulator of classical and nonclassical MHC class I molecules. HNRNPR is a RNA-binding protein belonging to the heterogeneous nuclear ribonucleoprotein family, which has a known role in processing of precursor mRNA. We demonstrated that HNRNPR binds MHC class I mRNAs in their 3' untranslated regions and enhances their stability and consequently their expression. Furthermore, regulation by HNRNPR modulates the cytotoxic activity of NK cells. In conclusion, we show that HNRNPR acts as a general positive regulator of MHC class I expression.

RNA-binding proteins regulate the expression of the immune activating ligand MICB

The recognition of stress-induced ligands by the activating receptor NKG2D expressed on cytotoxic lymphocytes is crucial for the prevention and containment of various diseases and is also one of the best-studied examples of how danger is sensed by the immune system. Still, however, the mechanisms leading to the expression of the NKG2D ligands are far from being completely understood. Here, we use an unbiased and systematic RNA pull-down approach combined with mass spectrometry to identify six RNA-binding proteins (RBPs) that bind and regulate the expression of MICB, one of the major stress-induced ligands of NKG2D. We further demonstrate that at least two of the identified RBPs function during genotoxic stress. Our data provide insights into stress recognition and hopefully open new therapeutic venues.

Microscopic chromosome Xp distal deletions--a challenging issue in prenatal genetic counseling

OBJECTIVE

A prenatal diagnosis of chromosome X short arm deletions may present a challenge in prenatal genetic counseling. We present clinical and molecular data of carriers of Xp distal deletions.

METHODS

We assessed prenatal and postnatal phenotypes of individuals from three families with large Xp distal deletions and from a fourth family with a small Xp distal deletion. The work-up included karyotyping, chromosomal microarray analysis, and assessment of the X inactivation pattern.

RESULTS

Five out of eight women with large deletions had a short stature (<3rd percentile). Subjects from one family had developmental and emotional problems. All female carriers with small deletions had markedly short stature, whereas the men had mildly short stature. Chromosomal microarray analysis revealed 11.7-19.3 Mb deletions in three families and a small ~1 Mb deletion in the fourth. The pseudoautosomal region 1 of the X chromosome was deleted in two families with large deletions. X inactivation was skewed in all tested cases with large deletions.

CONCLUSION

Xp distal deletions are mainly associated with short stature. Skewing of the abnormal X chromosome may attenuate the phenotype in cases with large deletions. We suggest that prenatal evaluation in such cases should include sonographic follow-up and assessment of the X inactivation pattern.

Network dynamics predict improvement in working memory performance following donepezil administration in healthy young adults

Attentional selection in the context of goal-directed behavior involves top-down modulation to enhance the contrast between relevant and irrelevant stimuli via enhancement and suppression of sensory cortical activity. Acetylcholine (ACh) is believed to be involved mechanistically in such attention processes. The objective of the current study was to examine the effects of donepezil, a cholinesterase inhibitor that increases synaptic levels of ACh, on the relationship between performance and network dynamics during a visual working memory (WM) task involving relevant and irrelevant stimuli. Electroencephalogram (EEG) activity was recorded in 14 healthy young adults while they performed a selective face/scene working memory task. Each participant received either placebo or donepezil (5mg, orally) on two different visits in a double-blinded study. To investigate the effects of donepezil on brain network dynamics we utilized a novel EEG-based Brain Network Activation (BNA) analysis method that isolates location-time-frequency interrelations among event-related potential (ERP) peaks and extracts condition-specific networks. The activation level of the network modulated by donepezil, reflected in terms of the degree of its dynamical organization, was positively correlated with WM performance. Further analyses revealed that the frontal-posterior theta-alpha sub-network comprised the critical regions whose activation level correlated with beneficial effects on cognitive performance. These results indicate that condition-specific EEG network analysis could potentially serve to predict beneficial effects of therapeutic treatment in working memory.

Endurance exercise diverts the balance between Th17 cells and regulatory T cells

Endurance, marathon-type exertion is known to induce adverse changes in the immune system. Increased airway hyper-responsiveness and airway inflammation are well documented in endurance athletes and endurance exercise is considered a major risk factor for asthma in elite athletes. Yet, the mechanisms underlying this phenomenon are still to be deduced. We studied the effect of strenuous endurance exercise (marathon and half-ironman triathlon) on CD4+ lymphocyte sub-populations and on the balance between effector and regulatory CD4+ lymphocytes in the peripheral blood of trained athletes, Endurance exercise induced a significant increase in Th17 cells and a sustained decrease in peripheral blood regulatory T cells (Tregs). While interleukin (IL)-2 levels remained undetectable, post-race serum IL-6 and transforming growth factor (TGF) β levels were significantly elevated. Treg levels in sedentary controls' decreased in vitro after incubation with athletes' post-exercise serum, an effect that was attenuated by supplements of IL-2 or anti IL-6 neutralizing antibodies. Our data suggest that exercise-induced changes in serum cytokine levels promote alterations in Tregs and Th17 cell populations, which may divert the subtle balance in the immune system towards inflammation. This may explain allergic and autoimmune phenomena previously reported in endurance athletes and contribute to our understanding of exercise-related asthma.

High prevalence of malignant melanoma in Israeli patients with Parkinson's disease

The risk of melanoma is higher in patients with Parkinson's disease (PD) than in the general population. Whether the association is disease related or treatment related is unclear. The objective of this study was to assess melanoma prevalence in PD patients in Israel using active dermatologic screening. Consecutive patients with idiopathic PD were recruited by 12 Israeli centers. A movement disorder specialist assessed the severity of PD and obtained a medical, neurological, and medication history. Subsequently, a dermatologist assessed melanoma risk factors, recorded a dermatologic history, proactively performed a whole-body skin examination, and biopsied suspicious skin lesions. Of the enrolled patients (n = 1,395, mean age 69.5 ± 10.6 years, mean PD duration 7.3 ± 6.0 years), 95.3% were treated with dopaminergic agents. Biopsies revealed 8 patients with melanoma in situ and 1 with invasive malignant melanoma; 14 patients reported a melanoma prior to enrollment. The observed 5-year limited duration prevalence of melanoma in PD patients was 4.4 times greater (95% CI 2.6-7.6) than expected from melanoma prevalence in an age- and sex-matched cohort from the Israel National Cancer Registry. The increase was accounted for by an elevated prevalence of melanoma in situ [relative risk 12.5 (95% CI 6.7-23.2)]. Occurrence of melanoma did not correlate with levodopa therapy or time of onset of PD. Melanoma prevalence in PD patients was higher than expected in the general Israeli population. This was not related to levodopa treatment. PD patients should be actively screened for melanoma on a routine basis.

Resolving a genetic paradox throughout preimplantation genetic diagnosis for autosomal dominant severe congenital neutropenia

OBJECTIVE

Severe congenital neutropenia is an inherited disease characterized by low peripheral blood neutrophils, amenable to bone marrow transplantation. Genetic analysis in the family here described detected a ELA2 splice-site mutation in the affected child and also in his asymptomatic father. The parents requested preimplantation genetic diagnosis (PGD), coupled with HLA matching, to obtain a suitable bone marrow donor for the affected child.

METHODS

A PGD protocol was developed, based on multiplex nested PCR for direct analysis of the ELA2 mutation, flanking polymorphic markers and HLA typing.

RESULTS

The amplification efficiency of the mutation was > 90% in single leukocytes from the affected child but only 67% in the father. Analysis of single haploid sperm cells from the father demonstrated three different sperm-cell populations: (1) sperm cells harboring the ELA2 mutation on the 'affected' haplotype, (2) sperm cells without the ELA2 mutation on the 'normal' haplotype, and (3) sperm cells without the ELA2 mutation on the 'affected' haplotype.

CONCLUSION

These data demonstrate that the ELA2 mutation in the father occurred de novo during his embryonic development, resulting in somatic as well as germ-line mosaicism. This conclusion was also taken into consideration when PGD was performed.

Premature thelarche: age at presentation affects clinical course but not clinical characteristics or risk to progress to precocious puberty

OBJECTIVES

To determine whether age at premature thelarche (PT) onset affects the clinical characteristics, course, and risk of progression to precocious puberty (PP).

STUDY DESIGN

Data regarding course of growth and puberty were retrieved from the medical files of 139 girls with PT followed up from 1995 to 2005. Analysis was based on age at PT appearance (birth, 1-24 months, and 2-8 years); course was categorized as regressive, persistent, progressive, or cyclic.

RESULTS

At diagnosis, height standard deviation score, bone age-chronological age ratio, and hormonal values were comparable in the 3 age groups. PT regressed in 50.8%, persisted in 36.3%, progressed in 3.2% and had a cyclic course in 9.7%. A progressive or cyclic course was significantly more prevalent among girls presenting after 2 years (52.6%) compared with girls presenting at birth (13.0%) or at 1 to 24 months (3.8%) (P < .001). PP occurred in 13% irrespective of age at PT presentation or clinical course.

CONCLUSIONS

Clinical and anthropometric characteristics at admission and risk of PP were similar in all girls with PT, regardless of age at onset. There are currently no clinical or laboratory tests that can predict the risk of progression to PP at presentation.

Preimplantation genetic diagnosis for fragile X syndrome: is there increased transmission of abnormal FMR1 alleles among female heterozygotes?

BACKGROUND

Fragile X syndrome is caused by a CGG triplet-repeat expansion mutation in the FMR1 gene. Previous studies have shown increased transmission of abnormal alleles in the 51-60 repeat range. This study was undertaken to evaluate the performance of preimplantation genetic diagnosis (PGD) for fragile X, and to assess the transmission rate of the abnormal FMR1 alleles in this setting.

METHOD

The study included 18 fragile X carriers who applied for PGD. FMR1 CGG repeats ranged from 70 to 300. PGD was performed using multiplex-nested PCR, with simultaneous amplification of the CGG repeat region and several polymorphic markers, and sex chromosome markers.

RESULTS

Four patients had a poor ovarian response, and could not undergo PGD. The remaining 14 patients underwent 47 PGD cycles. A total of 565 oocytes were aspirated. Of the 386 embryos that were successfully biopsied, 18 (6.4%) could not be analyzed due to amplification failure, and 12 (4.3%) had sex chromosomal abnormalities. Of the remaining 250 embryos, the abnormal allele was transmitted to 124 embryos (49.6%) compared to 126 (50.4%) for the normal allele. This difference was not statistically significant. Only embryos carrying the normal allele were transferred, resulting in 7 clinical pregnancies (18% per embryo transfer).

CONCLUSIONS

Our results demonstrate that PGD for fragile X is feasible, and that carriers transmit the abnormal allele at the same frequency as the normal allele.

Sustained leukocyte count during rising cortisol level

AIMS

To follow the trend of leukocyte counts relative to the serum cortisol levels in hospitalized patients.

METHODS

We retrospectively reviewed the charts of 59 hospitalized patients who had sequential blood profiles during a 2-week period.

RESULTS

The study cohort was divided into two subgroups according to the categorical cortisol levels: those within the normal range (< 25 microg/dl; n = 31 patients) and those above the normal range (> or = 25 microg/dl; n = 28 patients). The baseline white blood cell counts (WBCCs) were similar in both groups. After 1 week, however, the WBCCs dropped significantly in the presence of normal cortisol levels and increased in the presence of elevated cortisol levels (p = 0.002). This pattern was not followed by the platelet counts. A significant correlation was observed between the cortisol levels and the 1 week concomitant WBCC (r = 0.33).

CONCLUSION

Cortisol may be the mechanism with a positive effect on the maintenance of elevated leukocyte counts.

Prenatal detection of congenital bilateral cataract leading to the diagnosis of Nance-Horan syndrome in the extended family

OBJECTIVES

To describe a family in which it was possible to perform prenatal diagnosis of Nance-Horan Syndrome (NHS).

METHODS

The fetus was evaluated by 2nd trimester ultrasound. The family underwent genetic counseling and ophthalmologic evaluation. The NHS gene was sequenced.

RESULTS

Ultrasound demonstrated fetal bilateral congenital cataract. Clinical evaluation revealed other family members with cataract, leading to the diagnosis of NHS in the family. Sequencing confirmed a frameshift mutation (3908del11bp) in the NHS gene.

CONCLUSION

Evaluation of prenatally diagnosed congenital cataract should include a multidisciplinary approach, combining experience and input from sonographer, clinical geneticist, ophthalmologist, and molecular geneticist.

Feto-feto-fetal transfusion syndrome in monozygotic monochorionic triamniotic triplets: vascular evaluation by a cast model

A unique cast model of the placenta in a rare case of feto-feto-fetal triplet transfusion syndrome (FFFTTS) allowed the demonstration of why the transfusion syndrome developed in one fetus and not in the other two in that single placenta. The vasculature anatomy of a monochorionic triamniotic triplet placenta with FFFTTS of three healthy infants (one donor, two recipients) born in the 35th week of gestation was cast by means of dental casting materials. After the cast hardened, the tissue was corroded, revealing the cast blood vessels. The diameters and lengths of the chorionic blood and intraplacental vessels of the cast placenta were measured with a digital caliper. The cast revealed two artery-artery (A-A) anastomoses on the chorionic plate between the two recipients and the donor. Seven artery-vein (A-V) deep anastomoses connected only the arteries of the donor and the veins of the two recipients. The blood vessel connections among the fetuses allowed the evaluation of a pathologic case with its own control in a single placenta. From the vascular appearance, we speculate that the A-A anastomoses between the two fetuses protected them from developing blood transfusions, but that the A-V anastomoses contributed to their development.