Fetal arthrogryposis-what do we tell the prospective parents?

Arthrogryposis, also termed arthrogryposis multiplex congenita, is a descriptive term for conditions with multiple congenital contractures (MCC). The etiology is extremely heterogeneous. More than 400 specific disorders have been identified so far, which may lead to or are associated with MCC and/or fetal hypo- and akinesia as a clinical sign. With improved sensitivity of prenatal ultrasound and expanding prenatal diagnostic options, clinicians are tasked with providing early detection in order to counsel the prospective parents regarding further prenatal diagnostic as well as management options. We summarize the most important knowledge to raise awareness for early detection in pregnancy. We review essential points for counseling when MCC is detected in order to provide answers to common questions, which, however, cannot replace interdisciplinary expert opinion in the individual case.

The role of ultrasound in first-trimester screening after the introduction of NIPT as a service of public health insurance - a consensus statement of the Fetal Medicine Foundation (FMF) Germany.

Combined first-trimester screening (FTS) and noninvasive prenatal testing (NIPT) have been proven to be reliable noninvasive procedures to detect the most common chromosomal abnormalities (trisomies 21, 18, 13) in the first trimester. The aim of this paper is to demonstrate the strengths and limitations of these two procedures and to give a consensus statement of the Fetal Medicine Foundation (FMF) Germany on how to use the two techniques in the first trimester after the introduction of NIPT as a service of the statutory health insurance companies in Germany.

How genomics is changing the practice of prenatal testing.

New genomic laboratory technology namely microarrays and high throughput sequencing (HTS) as well as a steady progress in sonographic image capture and processing have changed the practice of prenatal diagnosis during the last decade fundamentally. Pregnancies at high risk for common trisomies are reliably identified by non-invasive prenatal testing (NIPT) and expert sonography has greatly improved the assessment of the fetal phenotype. Preconceptional comprehensive carrier screening using HTS is available for all parents, if they should wish to do so. A definite fetal diagnosis, however, will still require invasive testing for most conditions. Chromosomal microarrays (CMA) have greatly enhanced the resolution in the detection of chromosome anomalies and other causal copy number variations (CNV). Gene panel or whole exome sequencing (WES) is becoming the routine follow up of many anomalies detected by ultrasound after CNVs have been excluded. The benefits and limitations of the various screening as well as diagnostic options are perceived as complex by many who find it challenging to cope with the need for immediate choices. The communication of facts to ensure an informed decision making is obviously a growing challenge with the advent of the new genomic testing options. This contribution provides an overview of the current practice and policies in Switzerland.

Fetal arthrogryposis: Challenges and perspectives for prenatal detection and management.

Antenatal identification of fetuses with multiple congenital contractures or arthrogryposis multiplex congenita (AMC) may be challenging. The first clinical sign is often reduced fetal movement and/or contractures, as seen on prenatal ultrasounds. This can be apparent at any point, from early to late pregnancy, may range from mild to severe involvement, with or without associated other structural anomalies. Possible etiologies and their prognosis need to be interpreted with respect to developmental timing. The etiology of AMC is highly heterogeneous and making the specific diagnosis will guide prognosis, counseling and prenatal and perinatal management. Current ultrasound practice identifies only approximately 25% of individuals with arthrogryposis prenatally before 24 weeks of pregnancy in a general obstetrics care population. There are currently no studies and guidelines that address the question of when and how to assess for fetal contractures and movements during pregnancy. The failure to identify fetuses with arthrogryposis before 24 weeks of pregnancy means that physicians and families are denied reproductive options and interventions that may improve outcome. We review current practice and recommend adjusting the current prenatal imaging and genetic diagnostic strategies to achieve early prenatal detection and etiologic diagnosis. We suggest exploring options for in utero therapy to increase fetal movement for ongoing pregnancies.

DEGUM, ÖGUM, SGUM and FMF Germany Recommendations for the Implementation of First-Trimester Screening, Detailed Ultrasound, Cell-Free DNA Screening and Diagnostic Procedures. / Empfehlungen der DEGUM, der ÖGUM, der SGUM und der FMF Deutschland zum Einsatz von Ersttrimester-Screening, früher Fehlbildungsdiagnostik, Screening an zellfreier DNA (NIPT) und diagnostischen Punktionen.

First-trimester screening between 11 + 0 and 13 + 6 weeks with qualified prenatal counseling, detailed ultrasound, biochemical markers and maternal factors has become the basis for decisions about further examinations. It detects numerous structural and genetic anomalies. The inclusion of uterine artery Doppler and PlGF screens for preeclampsia and fetal growth restriction. Low-dose aspirin significantly reduces the prevalence of severe preterm eclampsia. Cut-off values define groups of high, intermediate and low probability. Prenatal counseling uses detection and false-positive rates to work out the individual need profile and the corresponding decision: no further diagnosis/screening - cell-free DNA screening - diagnostic procedure and genetic analysis. In pre-test counseling it must be recognized that the prevalence of trisomy 21, 18 or 13 is low in younger women, as in submicroscopic anomalies in every maternal age. Even with high specificities, the positive predictive values of screening tests for rare anomalies are low. In the general population trisomies and sex chromosome aneuploidies account for approximately 70 % of anomalies recognizable by conventional genetic analysis. Screen positive results of cfDNA tests have to be proven by diagnostic procedure and genetic diagnosis. In cases of inconclusive results a higher rate of genetic anomalies is detected. Procedure-related fetal loss rates after chorionic biopsy and amniocentesis performed by experts are lower than 1 to 2 in 1000. Counseling should include the possible detection of submicroscopic anomalies by comparative genomic hybridization (array-CGH). At present, existing studies about screening for microdeletions and duplications do not provide reliable data to calculate sensitivities, false-positive rates and positive predictive values.

Strømme Syndrome Is a Ciliary Disorder Caused by Mutations in CENPF.

Strømme syndrome was first described by Strømme et al. (1993) in siblings presenting with "apple peel" type intestinal atresia, ocular anomalies and microcephaly. The etiology remains unknown to date. We describe the long-term clinical follow-up data for the original pair of siblings as well as two previously unreported siblings with a severe phenotype overlapping that of the Strømme syndrome including fetal autopsy results. Using family-based whole-exome sequencing, we identified truncating mutations in the centrosome gene CENPF in the two nonconsanguineous Caucasian sibling pairs. Compound heterozygous inheritance was confirmed in both families. Recently, mutations in this gene were shown to cause a fetal lethal phenotype, the phenotype and functional data being compatible with a human ciliopathy [Waters et al., 2015]. We show for the first time that Strømme syndrome is an autosomal-recessive disease caused by mutations in CENPF that can result in a wide phenotypic spectrum.

Improved Detection Rate of Ovarian Cancer Using a 2-Step Triage Model of the Risk of Malignancy Index and Expert Sonography in an Outpatient Screening Setting.

OBJECTIVE: Preoperative assessment of adnexal masses with ultrasound has been shown to be time-, cost-effective, and specific. When used in combination with the menopausal status and the tumor marker CA125, the risk of malignancy index (RMI) can be calculated, allowing appropriate preoperative triage of patients to a gynecologist or a gynecological oncologist. Moreover, it allows for accurate planning of the required surgical procedure (laparoscopy vs laparotomy). METHODS: A large general gynecologic ultrasonic database retrospectively identified 5218 patients for a 14-year period who presented to the outpatient clinic with an adnexal mass. Additional data (menopausal status, histology, CA125 values) were available in 1108 of these patients. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. The results were then compared with previously published data from a large Australian gynecological cancer center (GCC, n = 204). RESULTS: With the use of an RMI cutoff of 200, malignant ovarian tumors were correctly triaged to a gynecologic oncologist in 123 of 172 cases, leading to a sensitivity of 72% and specificity of 92% in our general outpatient clinic population compared with a sensitivity of 84% and a specificity of 77% in the GCC high-risk population. The negative predictive value was 95% compared with only 85% in the GCC cohort. We hypothesize that improvement of the overall detection rate of malignancy could be improved from 72% to 85% using a 2-step model, referring patients with an ultrasonic score of 3 to an experienced sonographer who uses pattern recognition. CONCLUSIONS: The RMI is an easy and reliable tool for the accurate triage of adnexal masses. Its value is higher in an unselected gynecological outpatient setting. Our proposed 2-step model including expert pattern recognition could influence particularly the detection rate in borderline and early-stage ovarian cancers and overcome the limitations of the tumor marker CA125.

The special role of ultrasound for screening, staging and surveillance of malignant ovarian tumors: distinction from other methods of diagnostic imaging.

Ovarian cancer is the most aggressive gynecologic malignancy, with a 5-year survival rate ranging around 40%. A crucial factor influencing the prognosis is early detection of a suspicious mass and referral to a gynecologic oncology center for further diagnosis, staging and debulking surgery. Here, we present the different imaging methods ultrasound (US), magnetic resonance imaging, computer tomography (CT) and 18F-fluoro-deoxyglucose positron emission tomography (PET)/CT that are used for the characterization, diagnosis, staging and surveillance of ovarian cancer. In this review, we focus on US and discuss in detail the advantages and the limitations, as well as the appropriate indications for each of the individual imaging techniques.

Determination of fetal chromosome aberrations from fetal DNA in maternal blood: has the challenge finally been met?

The analysis of cell-free fetal nucleic acids in maternal blood for prenatal diagnosis has been transformed by several recent profound technology developments. The most noteworthy of these are 'digital PCR' and 'next-generation sequencing' (NGS), which might finally deliver the long-sought goal of noninvasive detection of fetal aneuploidy. Recent data, however, indicate that NGS might even be able to offer a much more detailed appraisal of the fetal genome, including paternal and maternal inheritance of point mutations for mendelian disorders such as ß-thalassaemia. Although these developments are very exciting, in their current form they are still too complex and costly, and will need to be simplified considerably for their optimal translation to the clinic. In this regard, targeted NGS does appear to be a step in the right direction, although this should be seen in the context of ongoing progress with the isolation of fetal cells and with proteomic screening markers.

aCGH on chorionic villi mirrors the complexity of fetoplacental mosaicism in prenatal diagnosis.

OBJECTIVE: To describe the diagnostic performance of array comparative genomic hybridization (aCGH) in the presence of mosaicism in the fetoplacental unit using direct chorionic villi. METHOD: In an ongoing study on the diagnostic performance of aCGH in 80 high-risk pregnancies, we studied three cases of placental mosaicism by carrying out aCGH on DNA of direct chorionic villi and chorionic villi cultures. RESULTS: Case 1: A three- to fourfold dosage gain of the region 18p in aCGH on direct villi was due to two additional isochromosomes 18p confined to the cytotrophoblast. Case 2: aCGH on direct villi revealed a normal result, whereas trisomy 18 mosaicism was present in cultured cells. Case 3: aCGH identifies monosomy X and mosaic disomy of the region Xp11.21-Xq12, whereas this mosaic cell line is not present in the conventional chromosome preparation on the cytotrophoblast. CONCLUSION: Although interpretation of aCGH results may be straightforward in the majority of cases, placental mosaicism may cause misinterpretations of rapid aCGH results on direct chorionic villi due to discrepant chromosomal constitutions of cytotrophoblast and mesenchymal villus core. Further investigations including cultures, fluorescence in situ hybridization and possible amniocentesis will still be required for interpretation of results.

Fetal polydactyly: a study of 24 cases ascertained by prenatal sonography.

Records of 24 pregnancies with fetal polydactyly were reviewed for the type of polydactyly, family history, associated sonographic findings, genetic testing, and postnatal/postmortem examination findings. The importance of fetal polydactyly can be mainly elucidated by the family history and absent or associated anomalies on a specialized malformation scan. Fetal karyotyping diagnoses frequent chromosomal anomalies in about half of cases with additional malformations, and array comparative genomic hybridization may be a future means of detecting cryptic chromosomal aberrations. Syndromic disorders of monogenic origin demand a careful interdisciplinary clinical assessment for establishing a clinical diagnosis and prognosis for the outcome of the child.