Prenatal diagnosis of acrania/exencephaly/anencephaly sequence (AEAS): additional structural and genetic anomalies.

OBJECTIVES: To analyse additional structural and genetic anomalies in fetuses with acrania/exencephaly/anencephaly sequence (AEAS). METHODS: A retrospective analysis of 139 fetuses with AEAS diagnosed between 2006 and 2020 in a single tertiary referral ultrasound department. RESULTS: The median gestational age at diagnosis decreased from 15 weeks in 2006 to 13 weeks in 2020 (- 0.21 per each year; p = 0.009). In 103 fetuses, the defects were limited to the neural tube (NTD) (74.1%), in 36 fetuses (25.9%), there were additional structural non-NTD anomalies. The most common were ventral body wall defects present in 17.8% (23/139), followed by anomalies of the limbs (7.2%; 10/139), face (6.5%; 9/139) and heart (6.5%; 9/139). Genetic anomalies were diagnosed in 7 of the 74 conclusive results (9.5%; 7/74; trisomy 18, n = 5; triploidy, n = 1; duplication of Xq, n = 1). In univariate logistic regression models, male sex, limb anomalies and ventral body wall defects significantly increased the risk of genetic anomalies (OR 12.3; p = 0.024; OR 16.5; p = 0.002 and OR 10.4; p = 0.009, respectively). CONCLUSIONS: A significant number of fetuses with AEAS have additional structural non-NTD anomalies, which are mostly consistent with limb body wall complex. Genetic abnormalities are diagnosed in almost 10% of affected fetuses and trisomy 18 is the most common aberration. Factors that significantly increased the odds of genetic anomalies in fetuses with AEAS comprise male sex, limb anomalies and ventral body wall defects.

Prenatal diagnosis of Emanuel syndrome - case series and review of the literature.

We present three new cases and review of the literature on the prenatal diagnosis of Emanuel syndrome (ES). Twenty-one foetuses have been analysed. In all three cases diagnosed in our department, posterior fossa abnormalities were seen and in one hypoplastic right ventricle was diagnosed at the first trimester scan. Defects of the posterior fossa (62% of foetuses; 13/21) and left diaphragmatic hernia (29% of foetuses; 6/21) are the most frequently reported prenatal findings in ES syndrome. No pattern of specific prenatal ultrasound markers of ES exists. Abnormalities of the posterior fossa are frequent and may be diagnosed as early as in the first trimester of pregnancy. Specific diagnosis can be made only after invasive genetic testing.IMPACT STATEMENTWhat is already known on this subject? Emanuel syndrome (ES) is a rare genetic disorder. No pattern of specific prenatal ultrasound markers exists. The great majority of cases is diagnosed postnatally and only a few cases of prenatal diagnosis have been published to date.What do the results of this study add? The most frequent structural abnormalities in prenatally detected ES involved central nervous system (80.9%), namely posterior fossa defects (57.1%) and mild ventriculomegaly (23.8%). Other frequent abnormalities include left diaphragmatic hernia (28.6%), renal defects (23.8%) and foetal growth restriction (FGR) (23.8%).What are the implications of these findings for clinical practice and/or further research? Abnormalities of the posterior fossa are the most frequent defects in ES and may be diagnosed as early as in the first trimester of pregnancy. Specific diagnosis can be made only after invasive genetic testing.

Triploid pregnancy-Clinical implications.

Triploidy is a life-limiting genetic aberration resulting from an extra haploid set of chromosomes of paternal (diandric triploidy) or maternal origin (digynic triploidy). Triploidy affects around 1%-2% of all conceptions. The majority of cases is miscarried at early developmental stages. In consequence of genomic imprinting, parental origin affects the phenotype of triploid pregnancies as well as the prevalence and spectrum of related maternal complications. Distinctive ultrasound features of both triploid phenotypes as well as characteristic patterns of biochemical markers may be useful in diagnosis. Molecular confirmation of the parental origin allows to predict the risk of complications, such as gestational trophoblastic neoplasia, hyperthyroidism, hypertension, or preeclampsia associated with the paternal origin of triploidy. Diagnosis of partial hydatidiform mole associated with diandric triploidy is challenging especially in the first trimester pregnancy loss due to the limitations of both histopathology and ultrasound. We present important clinical aspects of triploid pregnancies and indicate unresolved issues demanding further studies.

Distribution of diandric and digynic triploidy depending on gestational age.

PURPOSE: To establish the distribution of diandric and digynic triploidy depending on gestational age. METHODS: 107 triploid samples tested prospectively in a single genetic department during a four-year period were analyzed for parental origin of triploidy by Quantitative Fluorescent Polymerase Chain Reaction (QF-PCR) (n=95) with the use of matching parental samples or by MS-MLPA (n=12), when parental samples were unavailable. Tested pregnancies were divided into three subgroups with regard to the gestational age at spontaneous pregnancy loss: <11 gestational weeks, 11-14 gestational weeks, and >14 gestational weeks. RESULTS: Diandric triploidy constituted overall 44.9% (46.5% in samples miscarried <11 gestational weeks, 64.3% in samples miscarried between 11 and 14 gestational weeks, and 27.8% in pregnancies which survived >14 gestational weeks). CONCLUSIONS: The distribution of diandric and digynic triploidy depends on gestational age. The majority of diandric triploid pregnancies is lost in the first trimester of pregnancy. In the second trimester, diandric cases are at least twice less frequent than digynic ones.

Usefulness of methylation-specific multiplex ligation-dependent probe amplification for identification of parental origin of triploidy.

Triploidy is a genetic aberration resulting from an extra haploid set of chromosomes of paternal (diandric) or maternal (digynic) origin. Diandric cases, opposite to digynic ones, may lead to gestational trophoblastic neoplasia (GTN) or generate maternal complications, therefore their identification is crucial, but reproducibility of traditionally used histopathological assessment is poor. The aim of the study was to analyse the usefulness of methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) with probes for two differentially methylated regions (DMR) at chromosome 11p.15.5 for identification of the parental origin of triploidy. 84 triploid DNA samples were tested with MS-MLPA: 34 paternal cases (40.5%) and 50 maternal ones (59.5%) according to the reference results of QF-PCR. Methylation ratio (MR) was calculated. Reference values proposed by the MRC-Holland for diploid samples (MR 0.8-1.2) were used. The values outside these ranges were used to diagnose parental origin of triploidy-paternal (MR > 1.2) or maternal (MR < 0.8). The effectiveness of MS-MLPA was 94.0%. The mean MR in paternal triploidy was 1.7 (SD-0.25; n = 34) compared with 0.56 in maternal triploidy (SD-0.12; n = 50). MR values in paternal and maternal triploidy did not overlap. In five samples (6.0%) parental origin of triploidy could not be accurately established by MS-MLPA, probably due to the maternal cell contamination (MCC). MS-MLPA can be used as a convenient method for distinguishing between paternal and maternal triploidy without the necessity for parental samples testing. It enables adequate selection of the paternal triploid cases for follow up in order to exclude post-molar GTN.

Prenatal diagnosis and clinical significance of cephalocele-A single institution experience and literature review.

OBJECTIVES: To determine the frequency of genetic and additional structural abnormalities as well as pregnancy outcomes in fetuses with prenatally diagnosed cephalocele. METHODS: A retrospective analysis of data retrieved from ultrasound examinations and genetic testing in fetuses with cephalocele diagnosed between 2006 and 2018 in a tertiary referral hospital along with a systematic literature search in the PubMed database on fetuses with prenatally diagnosed cephalocele. RESULTS: Twenty-one out of 36 fetuses were found to have additional structural anomalies (58.3%). In four fetuses, anomalies were consistent with limb-body wall complex, in five with Meckel-Gruber syndrome, and in one with amniotic band syndrome. Genetic abnormalities were present in 11.1% of fetuses (trisomy 6; microdeletion 22q11.21; microduplication 16p13.11; pathogenic variant in gene CC2D2A). Twenty-eight pregnancies were terminated (77.8%; 28/36); two were miscarried (5.6%; 2/36). All six children from pregnancies that continued were liveborn but only two survived the surgery and developed neurological sequence. Overall survival rate was 25% (2/8) with 0% intact survival. CONCLUSIONS: Additional structural anomalies are common in fetuses with cephalocele. A significant number of fetuses have genetic abnormalities, and a detailed genetic testing should be performed in all cases. The prognosis is poor with high mortality rate and 0% intact survival.

In-house genetic counseling increases the detection of abnormal karyotypes-a 26-year experience in prenatal diagnosis in a single tertiary referral hospital in Poland.

PURPOSE: To evaluate the trends in prenatal diagnosis over 26 years in a tertiary referral hospital. METHODS: A retrospective analysis of invasive prenatal procedures performed between 1991 and 2016. Maternal characteristics, indications for invasive diagnosis, and percentage of abnormal karyotypes were compared between periods according to guidelines implemented nationally and locally. RESULTS: A total of 14,302 invasive prenatal procedures were performed. The proportion of invasive procedures performed for advanced maternal age, abnormal karyotype in a previous pregnancy, and maternal anxiety decreased from 71.1%, 17.8%, 8.9% in 1991 to 23.9%, 1.3%, and 2.3% in 2016 (OR 0.6, 0.8, and 0.9 for each 5 years, respectively; p < 0.001), while the proportion of invasive procedures performed for abnormal ultrasound increased from 2.2% in 1991 to 51.6% in 2016 (OR 1.9 for each 5 years; p < 0.001). Abnormal karyotype was found in 9.7%. The proportion of abnormal karyotypes increased significantly from 0.0% in 1991 to 15.7% in 2016 (OR 1.35 for each 5-year period; p < 0.001). The odds of abnormal karyotype increased after the implementation of the Ordinance of the Minister of Health in 2003 (OR 1.6), the National Prenatal Screening Program in 2007 (OR 2.2), and the in-house genetic counseling with combined first trimester screening in 2015 (OR 3.1). CONCLUSIONS: Significant changes in prenatal diagnosis led to a better selection of patients undergoing invasive prenatal procedures. The implementation of in-house genetic counseling was associated with an increased rate of the detection of abnormal karyotypes.

The location of the fetal ears: A hint for prenatal diagnosis of agnathia-otocephaly complex.

Otocephaly is an extremely rare lethal congenital anomaly characterized by the absence or underdevelopment of the mandible. The clinical presentation is variable. Some cases may present with severe micrognathia as the only anomaly seen prenatally. The key to early diagnosis is careful assessment of the location of the fetal ears on 2D ultrasound examination.

Complex malformations involving the fetal body wall - definition and classification issues.

OBJECTIVE: The objective of the study is to analyse the sonographic features, cytogenetic results and pregnancy outcomes in complex malformations involving the body wall in a large cohort of fetuses with regard to different definitions proposed in the literature. METHOD: A retrospective study on 96 fetuses with complex malformations comprising ventral wall, craniofacial structures, limbs and umbilical cord that were evaluated between 1997 and 2015. RESULTS: The most common sonographic finding was an extensive ventral wall defect (95.8%; 92/96) comprising liver (94.6%; 87/92), intestine (82.6%; 76/92), heart (17.4%; 16/92) and bladder (8.7%; 8/92). Acrania and encephalocoele were observed in 24 and 9 fetuses (25.0%, 24/96; 9.4%, 9/96), respectively. Limb anomalies were present in 54 fetuses (56.3%; 54/96). Rudimentary or absent umbilical cord was observed in 62 fetuses (64.6%; 62/96). In 79 fetuses, there were additional multiple structural anomalies detected prenatally. None of the currently used definitions encompasses all possible phenotypes of body wall defects present in our cohort. Chromosomal aberrations were seen in 8 out of 60 cases with conclusive cytogenetic result (13.3%, 8/60). CONCLUSION: Chromosomal anomalies are common, and karyotyping should be offered. There is a need for a more rigorous classification of complex malformations in order to better understand the underlying pathophysiology. © 2017 John Wiley & Sons, Ltd.

Targeted prenatal diagnosis of Pallister-Killian syndrome.

OBJECTIVE: To present five new cases of prenatally diagnosed Pallister-Killian syndrome (PKS) and to propose an approach for a targeted diagnosis. METHOD: We retrospectively analyzed ultrasound findings and cytogenetic results in PKS. We also searched through dysmorphology databases for features occurring in PKS that could potentially be seen in prenatal ultrasound examination. RESULTS: On the basis of collected data, frequent and distinctive features in fetuses with PKS were established. The most appropriate material and method of testing were proposed. Rhizomelic limb shortening, diaphragmatic hernia, thickened nuchal fold, increased prenasal thickness, polydactyly and polyhydramnios were frequent and distinctive findings in fetuses with PKS. Amniocentesis was the most frequent prenatal procedure for material collection. Percentage of aneuploid cells was higher in amniotic fluid than in cord blood. Cytomolecular tests were useful as confirmation as well as preliminary tests. Cytogenetic identification of the isochromosome was done in all cases except one. CONCLUSIONS: In case of ultrasound evaluation of features frequent and distinctive for PKS in second and third trimesters of pregnancy, targeted diagnosis should be considered. Amniotic fluid instead of cord blood collection is preferable. Communication with the laboratory is important because modification of routine procedures enhances a chance for correct diagnosis. © 2017 John Wiley & Sons, Ltd.

Blue Rubber Bleb Nevus Syndrome Diagnosed Prenatally as an Epignathus.

The authors present a clinical report of the giant fetal tumor protruding from the oral cavity diagnosed sonographically at 32 weeks of gestation as an epignathus. After delivery, tumor proved to be a presentation of the blue rubber bleb nevus syndrome. To the best of our knowledge, the literature offers no reports on similar cases.

Clinical significance of the prenatal double bubble sign - single institution experience.

OBJECTIVE: The objective of this study is to determine the risk of aneuploidy, associated structural anomalies, and pregnancy outcome in the presence of prenatal double bubble sign detection. METHOD: We have performed a retrospective study on ultrasound reports and pregnancy outcomes in 42 fetuses with double bubble sign examined in our ultrasound department between 1998 and 2013. RESULTS: Additional major defects or aneuploidy markers were present in 24 fetuses. Chromosomal abnormalities occurred in 21 cases. There were 35 live births; two pregnancies ended in intrauterine fetal demise; five patients opted for termination of pregnancy because of additional anomalies or abnormal karyotype. Postnatal or postmortem verification revealed duodenal obstruction secondary to intrinsic or extrinsic cause in 40 cases; in one case, proximal jejunal atresia was diagnosed, and one neonate had normal bowel. CONCLUSIONS: Sonographic double bubble sign is associated with a significant rate of major anatomic defects, abnormal karyotype, and unfavorable pregnancy outcome. It is strongly indicative of duodenal obstruction.

[Maternal blood intrauterine transfusions in the therapy of red-cell alloimmunization performed in three difficult cases]. / Wykorzystanie krwi matczynej do transfuzji doplodowych w terapii konfliktu serologicznego na przykladzie trzech trudnych przypadków.

Maternal alloimmunization can lead to hemolytic anemia, hydrops fetalis and even fetal or neonatal death. Intrauterine treatment is possible and effective even though it is associated with some risk. We present a rare method of maternal blood intrauterine transfusions in the therapy of three difficult cases of erythroblastosis fetalis. The aim of this report was to present an alternative to volunteer donors. In severe cases, i.e. in the absence of matching blood types from the donor in the presence of multiple alloantibodies in the pregnant woman or if multiple transfusions are required, this can be the only therapeutic option. To the best of our knowledge, this has been the first publication on maternal blood donation for intrauterine transfusion in the Polish literature.

Prenatal diagnosis of craniosynostosis (compound Saethre-Chotzen syndrome phenotype) caused by a de novo complex chromosomal rearrangement (1; 4; 7) with a microdeletion of 7p21.3-7p15.3, including TWIST1 gene--a case report.

Craniosynostosis (a premature fusion of the cranial sutures) occurs with a frequency of 1 in 2100-2500 births and in over 40% cases is caused by known genetic factors--either single gene mutations or chromosomal rearrangements. Cases caused by complex chromosomal abnormalities are uncommon and likely associated with compound phenotype. Saethre-Chotzen syndrome (SCS) [#101400] is caused by TWIST1 gene haploinsufficiency. Its phenotype includes uni- or bicoronal synostosis, short stature, facial dysmorphism and variable anomalies of the hands and feet. Due to its poor sonographic manifestation a prenatal diagnosis of SCS is challenging. We report a case of a prenatally detected craniosynostosis (compound Saethre-Chotzen syndrome phenotype) caused by a de novo complex chromosomal rearrangement (1; 4; 7) with a microdeletion of 7p21.3-7p15.3, including TWIST1 gene.

[Aberrant right subclavian artery (ARSA)--a new sonographic marker for chromosomal aberrations in the second trimester--preliminary observations]. / Bladzaca prawa tetnica podobojczykowa--nowy marker aberracji chromosomowych w badaniu USG drugiego trymestru--wstepne obserwacje na materiale wlasnym.

OBJECTIVES: Presentation of our own, preliminary experiences in the assessment of the right subclavian artery's (RSA) position during the second trimester scan. MATERIAL AND METHODS: Since January 2012 our center has started to conduct the assessment of the position of the right subclavian artery in the second trimester scan. Patients who were diagnosed with an aberrant right subclavian artery (ARSA) were referred to invasive method of prenatal diagnosis. Abnormal karyotype and microdeletion 22q11 were analyzed. Detailed echocardiography was conducted in each case. RESULTS: Between January 2012 and September 2013 we diagnosed 19 cases of ARSA. There were three cases of congenital heart defect (15.8%; 3/19) (ventricular septal defect--VSD, n=2, atrioventricular septal defect--AVSD, n=1). Two out of 17 cases showed an abnormal karyotype (11.8%; 2/17)--46,XY del(5) (q15q31) and 47,XX+18. No 22q11.2 deletions were observed. Two patients did not consent to invasive methods of prenatal diagnosis. CONCLUSIONS: The position of the right subclavian artery (RSA) should be routinely assessed during the second trimester of ultrasound screening. The presence of ARSA increases the risk for abnormal karyotype in the fetus and therefore, all patients who are diagnosed with ARSA should be referred to the reference center.

[Non-invasive prenatal diagnosis of the most common aneuploidies with cell-free fetal DNA in maternal serum--preliminary results]. / Nieinwazyjna diagnostyka prenatalna najczestszych aneuploidii na podstawie plodowego DNA we krwi matki --doniesienie wstepne.

OBJECTIVES: The aim of the study was to present initial results of non-invasive prenatal diagnosis of common aneuploidies of chromosomes 21, 18 and 13 based on cell-free fetal DNA in maternal serum in high-risk patients, and to compare the results with routine karyotyping. MATERIAL AND METHODS: Before the invasive procedure, 10 ml of peripheral blood from 10 patients was collected to isolate cell-free fetal DNA and to perform a non-invasive fetal trisomy test (NIFTY provided by Beijing Genomics Institute, BGI, Shenzen, China). RESULTS: Three out of 10 samples showed an abnormal karyotype in traditional karyotyping. There were 9 conclusive NIFTY results. NIFTY detected 1 out of 2 trisomies 18. The quantity of cell-free fetal DNA in maternal plasma in the second probe with trisomy 18 was unsatisfactory fora conclusive NIFTY result. In 1 case traditional karyotyping revealed mosaicism impossible to detect with NIFTY

Implementation of Exome Sequencing in Prenatal Diagnosis and Impact on Genetic Counseling: The Polish Experience.

BACKGROUND: Despite advances in routine prenatal cytogenetic testing, most anomalous fetuses remain without a genetic diagnosis. Exome sequencing (ES) is a molecular technique that identifies sequence variants across protein-coding regions and is now increasingly used in clinical practice. Fetal phenotypes differ from postnatal and, therefore, prenatal ES interpretation requires a large amount of data deriving from prenatal testing. The aim of our study was to present initial results of the implementation of ES to prenatal diagnosis in Polish patients and to discuss its possible clinical impact on genetic counseling. METHODS: In this study we performed a retrospective review of all fetal samples referred to our laboratory for ES from cooperating centers between January 2017 and June 2021. RESULTS: During the study period 122 fetuses were subjected to ES at our institution. There were 52 abnormal ES results: 31 in the group of fetuses with a single organ system anomaly and 21 in the group of fetuses with multisystem anomalies. The difference between groups was not statistically significant. There were 57 different pathogenic or likely pathogenic variants reported in 33 different genes. The most common were missense variants. In 17 cases the molecular diagnosis had an actual clinical impact on subsequent pregnancies or other family members. CONCLUSIONS: Exome sequencing increases the detection rate in fetuses with structural anomalies and improves genetic counseling for both the affected couple and their relatives.

Comparative Genomic Hybridization to Microarrays in Fetuses with High-Risk Prenatal Indications: Polish Experience with 7400 Pregnancies.

The aim of this study was to determine the suitability of the comparative genomic hybridization to microarray (aCGH) technique for prenatal diagnosis, but also to assess the frequency of chromosomal aberrations that may lead to fetal malformations but are not included in the diagnostic report. We present the results of the aCGH in a cohort of 7400 prenatal cases, indicated for invasive testing due to ultrasound abnormalities, high-risk for serum screening, thickened nuchal translucency, family history of genetic abnormalities or congenital abnormalities, and advanced maternal age (AMA). The overall chromosomal aberration detection rate was 27.2% (2010/7400), including 71.2% (1431/2010) of numerical aberrations and 28.8% (579/2010) of structural aberrations. Additionally, the detection rate of clinically significant copy number variants (CNVs) was 6.8% (505/7400) and 0.7% (57/7400) for variants of unknown clinical significance. The detection rate of clinically significant submicroscopic CNVs was 7.9% (334/4204) for fetuses with structural anomalies, 5.4% (18/336) in AMA, 3.1% (22/713) in the group of abnormal serum screening and 6.1% (131/2147) in other indications. Using the aCGH method, it was possible to assess the frequency of pathogenic chromosomal aberrations, of likely pathogenic and of uncertain clinical significance, in the groups of cases with different indications for an invasive test.

Twin pregnancies discordant for digynic triploidy - A case series.

OBJECTIVE: To analyse natural course and perinatal management in twin pregnancies discordant for digynic triploidy. CASE REPORT: We present five cases of twins discordant for digynic triploidy. Pregnancy outcome was known for three of them. In one case, premature rupture of membranes occurred at 20 gestational weeks and both fetuses were miscarried. In two other pregnancies healthy co-twins were born at term after the triploid fetuses demise at 28 and 37 weeks. No maternal complications were observed. CONCLUSION: Twin pregnancies discordant for triploidy poses a challenge for perinatal management. Expectant management should be considered in digynic triploid cases.

Prenatal diagnosis of glutaric acidemia type 2 with the use of exome sequencing - an up-to-date review and new case report.

INTRODUCTION: Inborn errors of metabolism (IEM) also called metabolic diseases constitute a large and heterogenous group of disorders characterized by a failure of essential cellular functions. Antenatal manifestation of IEM is absent or nonspecific, which makes prenatal diagnosis challenging. Glutaric acidemia type 2 (GA2) is a rare metabolic disease clinically manifested in three different ways: neonatal-onset with congenital anomalies, neonatal-onset without congenital anomalies and late-onset. Neonatal forms are usually lethal. Congenital anomalies present on prenatal ultrasound as large, hyperechoic or cystic kidneys with reduced amniotic fluid volume. MATERIAL AND METHODS: We present a systematic literature review describing prenatal diagnosis of GA2 and a new prenatal case. RESULTS: Ten prenatally diagnosed cases of GA2 have been published to date, mainly based on biochemical methods. New case of GA2 was diagnosed using exome sequencing method. DISCUSSION: All prenatal cases from literature review had positive history of GA2 running in the family. In our study trio exome sequencing was performed in case of fetal hyperechoic kidneys without a history of GA2. Consequently, we were able to identify two novel pathogenic variants of the ETFDH gene and to indicate their parental origin. SUMMARY: Exome sequencing approach used in case of fetal hyperechoic kidneys allows to identify pathogenic variants without earlier knowledge of the precise genetic background of the disease. Hyperechoic, enlarged kidneys could be one of the clinical features of metabolic diseases. After exclusion of chromosomal abnormalities, urinary tract obstruction and intrauterine infections, glutaric acidemia type 2 and number of monogenic disorders should be consider.