Fetal arthrogryposis: Challenges and perspectives for prenatal detection and management

Pregnancy in myasthenia gravis: a retrospective analysis of maternal and neonatal outcome from a large tertiary care centre in Germany

PURPOSE

Myasthenia gravis (MG) is a rare, potentially life-threatening autoimmune disease with fluctuating muscle weakness frequently affecting women of childbearing age. MG can affect maternal as well as neonatal outcome with risk of worsening of myasthenic symptoms in the mothers and risk of transient neonatal myasthenia gravis (TNMG) and arthrogryposis multiplex congenita (AMC) or foetal acetylcholine receptor antibody-associated disorders (FARAD) in the neonates.

METHODS

Retrospective analysis of maternal and neonatal outcome in a cohort of pregnant MG patients treated at a tertiary care centre in Germany.

RESULTS

Overall, 66 pregnancies were analysed. During 40 (63%) pregnancies, women experienced a worsening of myasthenic symptoms, of whom 10 patients (15.7%) needed acute therapy with IVIg or plasma exchange. There was no case of myasthenic crisis. Rate of caesarean section was comparable to the overall C-section rate at our centre (38% vs. 40%). However, there was a slightly higher rate for operative vaginal delivery (15% vs. 10%) as potential indicator for fatiguing striated musculature in MG patients during the expulsion stage. Rate of TNMG as well as AMC was 3% (two cases each).

CONCLUSIONS

Maternal and neonatal outcome in our cohort was favourable with a low rate of myasthenic exacerbations requiring acute therapies and a low rate of TNMG and AMC/FARAD. Our data might help neurologists and obstetricians to advice MG patients with desire to have children.

Clinical and molecular characteristics of 26 fetuses with lethal multiple congenital contractures

Multiple congenital contractures (MCC) due to fetal akinesia manifest across a broad spectrum of diseases, ranging from mild distal arthrogryposis to lethal fetal akinesia deformation sequence. We hereby present a series of 26 fetuses displaying severe MCC phenotypes from 18 families and describe detailed prenatal ultrasound findings, postmortem clinical evaluations, and genetic investigations. Most common prenatal findings were abnormal facial profile (65%), central nervous system abnormalities (62%), polyhydramnios (50%), increased nuchal translucency (50%), and fetal hydrops (35%). Postmortem examinations unveiled additional anomalies including facial dysmorphisms, dysplastic skeletal changes, ichthyosis, multiple pterygia, and myopathy, allowing preliminary diagnosis of particular Mendelian disorders in multiple patients. Evaluation of the parents revealed maternal grip myotonia in one family. By exome sequencing and targeted testing, we identified causative variants in ACTC1, CHST14, COG6, DMPK, DOK7, HSPG2, KLHL7, KLHL40, KIAA1109, NEB, PSAT1, RAPSN, USP14, and WASHC5 in 15 families, and one patient with a plausible diagnosis associated with biallelic NEB variants. Three patients received a dual diagnosis. Pathogenic alterations in newly discovered genes or in previously known genes recently linked to new MCC phenotypes were observed in 44% of the cohort. Our results provide new insights into the clinical and molecular landscape of lethal MCC phenotypes.

Éléments de données communs pour l'arthrogrypose multiple congénitale: Un cadre international

Objectif

Afin de faciliter les études multisites et la recherche clinique d'envergure internationale, cette étude a pour but d'identifier des éléments de données communs (EDCs) normalisés et fondés sur un consensus pour l'arthrogrypose multiple congénitale (AMC).

Méthode

Une étude à méthodes mixtes comprenant plusieurs groupes de discussion et trois séries d'enquêtes Delphi modifiées pour parvenir à un consensus ont été menées.

Résultats

Dans l'ensemble, 45 experts cliniques ainsi qu'adultes ayant une expérience vécue (dont 12 membres d'un consortium d'AMC) ont participé à cette étude à travers 11 pays en Amérique du Nord, Europe et Australie. Les EDCs comprennent 321 éléments de données et 19 mesures standardisées dans divers domaines, du développement du fœtus à l'âge adulte. Les éléments de données relatifs aux traits phénotypiques de l'AMC ont été cartographiés conformément à l'ontologie du phénotype humain (HPO). Une structure de gouvernance universelle, des protocoles de fonctionnement et des plans de développement durable ont été identifiés comme les principaux facilitateurs considérant que la capacité limitée de partage des données et la nécessité d'une infrastructure informatique fédérée étaient les principaux obstacles.

Interprétation

Une collecte de données systématiques sur l'AMC à l'aide d'EDCs permettra d'étudier sur les voies étiologiques, décrire le profil épidémiologique, et établir des corrélations génotype‐phénotype de manière standardisée. Les EDCs proposés faciliteront les collaborations internationales multidisciplinaires en améliorant à grande échelle les études multicentriques, les possibilités de partage des données, ainsi que le transfert et la diffusion des connaissances.

Elementos de datos comunes para la artrogriposis múltiple congénita: Un marco internacional

Objetivo

Para facilitar los estudios multicéntricos y la investigación clínica internacional, este estudio pretende identificar de forma consensuada los elementos de datos estandarizados para la artrogriposis múltiple congénita (AMC).

Método

Estudio de métodos mixtos de grupos de discusión y tres rondas de encuestas Delphi modificadas para llegar a un consenso utilizando dos escalas de clasificación por niveles.

Resultados

En total, 45 expertos clínicos y adultos con experiencia vivida (incluidos 12 miembros de un consorcio de AMC) participaron en este estudio procedentes de 11 países: Norteamérica, Europa y Australia. Los CDEs incluyen 321 elementos de datos y 19 medidas estandarizadas en varios dominios desde el desarrollo fetal hasta la edad adulta. Los elementos de datos relativos a los rasgos fenotípicos del CDEs se mapearon de acuerdo con la Ontología de Fenotipos Humanos. Se identificaron como principales facilitadores la estructura de gobernanza universal, protocolos operados de forma local y los planes de sostenibilidad, mientras que los principales obstáculos observados son la capacidad limitada para compartir datos y la necesidad de una infraestructura informática federada.

Interpretación

La recopilación de datos sistemáticos sobre la AMC mediante CDEs permitirá investigar las vías etiológicas, describir el perfil epidemiológico y establecer correlaciones genotipo‐fenotipo de forma estandarizada. Los CDEs propuestos facilitarán las colaboraciones multidisciplinares internacionales mejorando los estudios a gran escala y las oportunidades para compartir datos, translación de conocimiento y difusión.

[Myasthenia gravis-Gender aspects and family planning]

BACKGROUND

There is evidence that gender-specific differences can influence the diagnostics, treatment and long-term disease course of myasthenia gravis (MG). In women the diagnosis is often made during childbearing age.

OBJECTIVE

Gender-specific differences in MG and relevant aspects in routine clinical practice are presented. In addition, current studies on family planning, pregnancy and childbirth in MG are highlighted and treatment recommendations are derived.

MATERIAL AND METHODS

Narrative literature review.

RESULTS

In addition to sociodemographic data, gender-specific differences encompass clinical as well as paraclinical factors, such as disease severity and antibody status. With few exceptions pregnancy is possible with good maternal and neonatal outcome. During pregnancy and peripartum, children of MG patients should be closely monitored for early detection and treatment of potential syndromes caused by diaplacental transfer of maternal antibodies.

CONCLUSION

Gender-specific factors can influence the course of MG. Adequate medical counselling and multidisciplinary collaboration are essential for MG patients who wish to have children.

Common data elements for arthrogryposis multiplex congenita: An international framework

AIM

To facilitate multisite studies and international clinical research, this study aimed to identify consensus-based, standardized common data elements (CDEs) for arthrogryposis multiplex congenita (AMC).

METHOD

A mixed-methods study comprising of several focus group discussions and three rounds of modified Delphi surveys to achieve consensus using two tiered-rating scales were conducted.

RESULTS

Overall, 45 clinical experts and adults with lived experience (including 12 members of an AMC consortium) participated in this study from 11 countries in North America, Europe, and Australia. The CDEs include 321 data elements and 19 standardized measures across various domains from fetal development to adulthood. Data elements pertaining to AMC phenotypic traits were mapped according to the Human Phenotype Ontology. A universal governance structure, local operating protocols, and sustainability plans were identified as the main facilitators, whereas limited capacity for data sharing and the need for a federated informatics infrastructure were the main barriers.

INTERPRETATION

Collection of systematic data on AMC using CDEs will allow investigations on etiological pathways, describe epidemiological profile, and establish genotype-phenotype correlations in a standardized manner. The proposed CDEs will facilitate international multidisciplinary collaborations by improving large-scale studies and opportunities for data sharing, knowledge translation, and dissemination.

Congenital hypotonia: systematic approach for prenatal detection

OBJECTIVES

Congenital hypotonic conditions are rare and heterogeneous, and some are severely debilitating or lethal. Contrary to its prominent postnatal manifestation, the prenatal presentation of hypotonia is frequently subtle, inhibiting prenatal detection. We aimed to characterize the prenatal sonographic manifestation of congenital hypotonia throughout pregnancy, evaluate the yield of diagnostic tests and propose diagnostic models to increase its prenatal detection.

METHODS

This was a retrospective observational study of singleton pregnancies with congenital hypotonia, diagnosed either prenatally or immediately after birth, at a single tertiary center between the years 2012 and 2020. Prenatally, hypotonia was diagnosed if a fetus showed sonographic or clinical signs suggestive of hypotonia and had a confirmed underlying genetic condition, or in the absence of a known genetic abnormality if the fetus exhibited multiple prominent signs suggestive of hypotonia. Postnatally, it was diagnosed in neonates displaying reduced muscle tone leading to reduced spontaneous movement, reduced swallowing or feeding difficulty. We reviewed the medical records of pregnant patients carrying fetuses subsequently diagnosed with congenital hypotonia and assessed the yield of ultrasound scans, fetal magnetic resonance imaging, computed tomography and genetic tests. The detection rate of sonographic signs suggesting fetal hypotonia was calculated. The prevalence of non-specific signs, including polyhydramnios, persistent breech presentation, intrauterine growth restriction and maternal perception of reduced fetal movement, were compared between the study group and the local liveborn singleton population. Potential detection rates of different theoretical semiotic diagnostic models, differing in the threshold for referral for a targeted scan, were assessed based on the cohort's data.

RESULTS

The study group comprised 26 cases of congenital hypotonia, of which 10 (38.5%) were diagnosed prenatally, and the controls included 95 105 singleton live births, giving a prevalence of congenital hypotonia of 1:3658. Nuchal translucency thickness and the early anomaly scan at 13-17 weeks were normal in all 22 and 23 cases, respectively, in which this was performed. The mid-trimester scan performed at 19-25 weeks was abnormal in four of 24 (16.7%) cases. The overall prenatal detection rate of congenital hypotonic conditions in our cohort was 38.5%. Only cases which underwent a targeted scan were detected and, among the 16 cases which underwent this scan, the prenatal detection rate was 62.5% compared with 0% in pregnancies that did not undergo this scan (P = 0.003). An abnormal genetic diagnosis was obtained in 21 (80.8%) cases using the following modalities: chromosomal microarray analysis (CMA) in two (9.5%), whole-exome sequencing (WES) in 14 (66.7%) and methylation analysis in five (23.8%). CMA was abnormal in 8% (2/25) of the cases and WES detected a causative genetic mutation in 87.5% (14/16) of the cases in which these were performed. Comparison of non-specific signs in the study group with those in the local singleton population showed that hypotonic fetuses had significantly more polyhydramnios (64.0% vs 3.0%, P < 0.0001), persistent breech presentation (58.3% vs 4.2%, P < 0.0001), intrauterine growth restriction (30.8% vs 3.0%, P < 0.0001) and maternal perception of reduced fetal movement (32.0% vs 4.7%, P < 0.0001). Prenatally, the most commonly detected signs supporting a diagnosis of hypotonia were structural anomaly (62.5%, 10/16), reduced fetal movement (46.7%, 7/15), joint contractures (46.7%, 7/15) and undescended testes ≥ 30 weeks (42.9%, 3/7 males). Proposed diagnostic strategies that involved performing a targeted scan for a single non-specific ultrasound sign or two such signs, and then carrying out a comprehensive genetic evaluation for any additional sign, offered theoretical detection rates in our cohort of 88.5% and 57.7%, respectively.

CONCLUSIONS

Congenital hypotonic conditions are rare and infrequently detected prenatally. Sonographic signs are visible from the late second trimester. A targeted scan increases prenatal detection significantly. Comprehensive genetic testing, especially WES, is the cornerstone of diagnosis in congenital hypotonia. Theoretical diagnostic models which may increase prenatal detection are provided. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

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.

Eye-tracking visual patterns of sonographers with and without fetal motor assessment expertise

OBJECTIVES

Fetal motor assessment (FMA) in addition to structural anomaly scan enhances prenatal detection of arthrogryposis multiplex congenita (AMC). In the Amsterdam UMC, sonographers are trained to perform FMA. We examined the effect of motor assessment training by comparing sonographers with (SMA) and without this training (S) on their qualitative motor assessment in fetuses with normal (FNM) and abnormal motility (FAM) and their visual processing by eye-tracking.

METHODS

The study was performed from 2019 to 2020. Five SMA and five S observed five FNM and five FAM videos. Qualitative FMA consisted of six aspects of the general movement and the overall conclusion normal or abnormal. The visual processing aspects examined through eye-tracking were fixation duration, number of revisits per region of interest (ROI) and scanpaths of saccades between fixation points.

RESULTS

Quality assessment by SMA revealed more correct aspects in FNM than in FAM but overall conclusions were equally correct (92-96 %). S scored aspects of FNM better than in FAM, but overall conclusion correct only in half of FNM and three quarters of FAM. Eye-tracking of SMA and S showed fixation duration and revisits with similar distributions per ROIs for FNM and FAM, but SMA perform more trunk revisits in FNM. Scanpaths had smaller circumference, less outliers and more consistency in SMA than S.

CONCLUSION

This modest population of qualified sonographers showed that additional FMA training improved qualitative motor assessment. Eye-tracking revealed differences in visual processing and stimulates continuous education for professionals active in the detection of these rare diseases.

Building a Co-ordinated Musculoskeletal System: The Plasticity of the Developing Skeleton in Response to Muscle Contractions

The skeletal musculature and the cartilage, bone and other connective tissues of the skeleton are intimately co-ordinated. The shape, size and structure of each bone in the body is sculpted through dynamic physical stimuli generated by muscle contraction, from early development, with onset of the first embryo movements, and through repair and remodelling in later life. The importance of muscle movement during development is shown by congenital abnormalities where infants that experience reduced movement in the uterus present a sequence of skeletal issues including temporary brittle bones and joint dysplasia. A variety of animal models, utilising different immobilisation scenarios, have demonstrated the precise timing and events that are dependent on mechanical stimulation from movement. This chapter lays out the evidence for skeletal system dependence on muscle movement, gleaned largely from mouse and chick immobilised embryos, showing the many aspects of skeletal development affected. Effects are seen in joint development, ossification, the size and shape of skeletal rudiments and tendons, including compromised mechanical function. The enormous plasticity of the skeletal system in response to muscle contraction is a key factor in building a responsive, functional system. Insights from this work have implications for our understanding of morphological evolution, particularly the challenging concept of emergence of new structures. It is also providing insight for the potential of physical therapy for infants suffering the effects of reduced uterine movement and is enhancing our understanding of the cellular and molecular mechanisms involved in skeletal tissue differentiation, with potential for informing regenerative therapies.

Fetuses and infants with Amyoplasia congenita in congenital Zika syndrome: The evidence of a viral cause. A narrative review of 144 cases

OBJECTIVES

Amyoplasia congenita is the most frequent type of arthrogryposis causing fetal hypokinesia, leading to congenital contractures at birth. The pathogenesis is thought to be impaired blood circulation to the fetus early in pregnancy, with hypotension and hypoxia damaging the anterior horn cells. In animal studies however a prenatal infection with a poliomyelitis-like viral agent was demonstrated. Congenital Zika virus syndrome (CZVS) has recently been described in infants with severe microcephaly, and in 10-25% of cases arthrogryposis.

METHODS

A search in PubMed for CZVS yielded 124 studies. After a selection for arthrogryposis, 35 papers were included, describing 144 cases. The studies were divided into two categories. 1) Those (87 cases) focussing on imaging or histological data of congenital brain defects, contained insufficient information to link arthrogryposis specifically to lesions of the brain or spinal motor neuron. 2) In the other 57 cases detailed clinical data could be linked to neurophysiological, imaging or histological data.

RESULTS

In category 1 the most frequent brain abnormalities in imaging studies were ventriculomegaly, calcifications (subcortical, basal ganglia, cerebellum), hypoplasia of the brainstem and cerebellum, atrophy of the cerebral cortex, migration disorders and corpus callosum anomalies. In category 2, in 38 of 57 cases clinical data were indicative of Amyoplasia congenita. This diagnosis was confirmed by electromyographic findings (13 cases), by MRI (37 cases) or histology (12 cases) of the spinal cord. The latter showed small or absent lateral corticospinal tracts, and cell loss and degeneration of motor neuron cells. Zika virus-proteins and flavivirus-like particles were detected in cytoplasm of spinal neurons.

CONCLUSION

The phenotype of arthrogryposis in CZVS is consistent with Amyoplasia congenita. These findings warrant search for an intrauterine infection with any neurotropic viral agent with affinity to spinal motor neurons in neonates with Amyoplasia.

Maternal perception of fetal movements: onset and associated factors

OBJECTIVES

The purpose of this study was to determine the onset of fetal movements' perception and to identify parameters that affect this timing.

METHODS

This was a prospective cohort study including singleton pregnancies that attended routine prenatal care, in a tertiary care center, in northern Greece, between January 2020 and July 2021. We collected data on medical and obstetric history, and invited women to record the time that they perceived the fetal movements for the first time, that being the primary outcome of the study. Furthermore, we studied the associations between this timing and several obstetric and sociodemographic parameters.

RESULTS

In total, 2,009 women participated in the study. The mean gestational age at first perception of fetal movements was 19 weeks (±1.5). This ranged from as early as 14⁺⁰-14⁺⁶ weeks (0.1%) to 24⁺⁰-24⁺⁶ weeks (0.1%). The majority of women (73.3%) reported initial perception of fetal movements between 18⁺⁰ and 20⁺⁶ weeks. Following multivariate logistic regression analysis, we found that nulliparity (OR: 2.607; 95% CI: 1.876-3.622; p<0.001), anterior placental position (OR: 1.918; 95% CI: 1.575-2.336; p<0.001), increasing body mass index (OR: 1.063; 95% CI: 1.040-1.088; p=0.001) and advancing maternal age (OR: 1.062; 95% CI: 1.040-1.084; p<0.001) were associated with a delayed perception of fetal movements. Multiparous women reported the onset of fetal movements almost one week earlier on average (18.6±1.4 weeks) compared to nulliparous (19.4±1.4 weeks; MD: 0.843; 95% CI: 0.718-0.968; p<0.001).

CONCLUSIONS

The onset of maternal perception of fetal movements is around 19 weeks and this timing may be delayed by higher maternal age, higher body mass index, nulliparity and anterior placental position.

Amyoplasia in monochorionic monozygotic pregnancy following interstitial laser

Amyoplasia is a specific form of arthrogryposis, without any genetic cause. Six to ten percent of amyoplasia cases are one of the monozygotic twins, with the other twin being normal. Failure of maturation of anterior horn cells (AHCs) due to ischemic injury has been postulated as the primary pathological change, leading to arrest in the development of muscle fibers supplied by the affected AHCs with the typical limb positioning seen in amyoplasia. Twin-to-twin transfusion syndrome (TTTS) is an important risk factor for ischemic injury in monozygotic twin pregnancies. We present a case of monochorionic diamniotic twin pregnancy with features of TTTS at 12 weeks who underwent interstitial laser followed by the development of lower limb akinesia in the surviving fetus. Possible causes of amyoplasia are discussed.

Congenital Dislocation of the Knee: Idiopathic or Arthrogryposis?

Fetal akinesia associated with fixed joints is a common cause for suspicion of arthrogryposis multiplex congenita, a severe condition with heterogeneous etiology. We present the case of a rarer but more benign condition, congenital knee dislocation.

The authors report the case of a 27-year-old woman medicated with levetiracetam for epilepsy whose prenatal ultrasound at 22 weeks of gestational age revealed bilateral clubfoot, permanent extension of the inferior limbs with internal knee rotation, normal amniotic fluid quantity, and fetal echocardiography. The remaining ultrasounds revealed similar results. Prenatal genetic testing revealed no pathological findings. The pregnancy was otherwise uneventful. A female newborn was delivered at 39 weeks by cesarean section, with no need for resuscitation. She presented with bilateral knee hyperextension and clubfoot, spontaneous movements, and normal mobility in all other joints. The remaining physical examination and brain and hip ultrasound on the second day of life were normal. These findings were compatible with idiopathic congenital dislocation of the knee (CDK). The patient was undergoing treatment with favorable evolution and adequate neurodevelopment, at the time of this report. 

This case describes a diagnostic workup with the exclusion of severe syndromic pathologies, namely arthrogryposis. Despite the initial suspicion of arthrogryposis, a condition with a poor prognosis, this infant presented a more benign disease with favorable evolution.

Clinical and Genetic Findings in a Series of Eight Families with Arthrogryposis

The term “arthrogryposis” is used to indicate multiple congenital contractures affecting two or more areas of the body. Arthrogryposis is the consequence of an impairment of embryofetal neuromuscular function and development. The causes of arthrogryposis are multiple, and in newborns, it is difficult to predict the molecular defect as well as the clinical evolution just based on clinical findings. We studied a consecutive series of 13 participants who had amyoplasia, distal arthrogryposis (DA), or syndromic forms of arthrogryposis with normal intellectual development and other motor abilities. The underlying pathogenic variants were identified in 11 out of 13 participants. Correlating the genotype with the clinical features indicated that prenatal findings were specific for DA; this was helpful to identify familial cases, but features were non-specific for the involved gene. Perinatal clinical findings were similar among the participants, except for amyoplasia. Dilatation of the aortic root led to the diagnosis of Loeys–Dietz syndrome (LDS) in one case. The phenotype of DA type 5D (DA5D) and Escobar syndrome became more characteristic at later ages due to more pronounced pterygia. Follow-up indicated that DA type 1 (DA1)/DA type 2B (DA2B) spectrum and LDS had a more favorable course than the other forms. Hand clenching and talipes equinovarus/rocker bottom foot showed an improvement in all participants, and adducted thumb resolved in all forms except in amyoplasia. The combination of clinical evaluation with Next Generation Sequencing (NGS) analysis in the newborn may allow for an early diagnosis and, particularly in the DAs, suggests a favorable prognosis.

Care pathway for fetal joint contractures, Fetal Akinesia Deformation Sequence and Arthrogryposis Multiplex Congenita

Introduction The majority of arthrogryposis multiplex congenita (AMC) and lethal forms of AMC such as fetal akinesia deformation sequence (FADS) cases are missed prenatally. We have demonstrated the additional value of fetal motor assessment and evaluation in a multidisciplinary team for the period 2007-2016. An applied care pathway for fetuses presenting with joint contracture(s) in one anatomic region (e.g. talipes equinovares), more than one body part with non-progressive contractures and motility (AMC) and with deterioration over time (FADS). Methods The multidisciplinary team of Amsterdam University Medical Centre Expertise Centre FADS and AMC developed the care pathway. Additional tools are provided including a motor assessment by ultrasound examination and postmortem assessment form. Results An eight-step care pathway is presented with a proposed timing for prenatal sonographic examination, genetic examinations, multidisciplinary meetings, prenatal and postnatal counselling of the parents by specialist also treating after birth, follow-up of prenatal and postnatal findings with counselling for future pregnancies. Discussion/conclusion The scheduled serial structural and motor sonograpahic assessment together with follow-up examinations and genetic analysis, should be tailored per prenatal centre per available resources. The multidisciplinary care pathway may pave the way to increase detection rate and diagnosis of isolated contracture(s), talipes equinovares with underlying genetic causes and the rare phenotypes AMC/FADS and prompt treatment after birth within expertise teams.

Joint development recovery on resumption of embryonic movement following paralysis

Fetal activity in utero is a normal part of pregnancy and reduced or absent movement can lead to long-term skeletal defects, such as Fetal Akinesia Deformation Sequence, joint dysplasia and arthrogryposis. A variety of animal models with decreased or absent embryonic movements show a consistent set of developmental defects, providing insight into the aetiology of congenital skeletal abnormalities. At developing joints, defects include reduced joint interzones with frequent fusion of cartilaginous skeletal rudiments across the joint. At the spine, defects include shortening and a spectrum of curvature deformations. An important question, with relevance to possible therapeutic interventions for human conditions, is the capacity for recovery with resumption of movement following short-term immobilisation. Here, we use the well-established chick model to compare the effects of sustained immobilisation from embryonic day (E)4-10 to two different recovery scenarios: (1) natural recovery from E6 until E10 and (2) the addition of hyperactive movement stimulation during the recovery period. We demonstrate partial recovery of movement and partial recovery of joint development under both recovery conditions, but no improvement in spine defects. The joints examined (elbow, hip and knee) showed better recovery in hindlimb than forelimb, with hyperactive mobility leading to greater recovery in the knee and hip. The hip joint showed the best recovery with improved rudiment separation, tissue organisation and commencement of cavitation. This work demonstrates that movement post paralysis can partially recover specific aspects of joint development, which could inform therapeutic approaches to ameliorate the effects of human fetal immobility. This article has an associated First Person interview with the first author of the paper.

Prenatal findings of cataract and arthrogryposis: recurrence of cerebro-oculo-facio-skeletal syndrome and review of differential diagnosis

BACKGROUND

Cerebro-oculo-facio-skeletal syndrome (COFS) is a severe and progressive neurologic condition characterized by prenatal onset of arthrogryposis, cataract, microcephaly and growth failure. The aim of this study was to present a case of recurrence of the COFS syndrome and to propose a differential diagnosis flow-chart in case of prenatal findings of arthrogryposis and cataract.

CASE PRESENTATION

We report a case of recurrence of COFS3 syndrome within the same family, with similar diagnostic features. In the first case the COFS syndrome remained undiagnosed, while in the second case, due to prenatal findings of arthrogryposis and cataract, genetic investigation focusing on responsible genes of COFS (ERCC5, ERCC6 and FKTN genes) was carried out. The fetus was found to be compound heterozygous for two different ERCC5 mutations, confirming the clinical suspect of COFS syndrome. A review of the literature on possible causative genes of prenatal cataract and arthrogryposis was performed and we present a flow-chart to guide differential diagnosis and possible genetic testing in case of these findings.

CONCLUSION

COFS syndrome is a rare autosomic recessive condition. However, it can be suspected and diagnosed prenatally. The flow-chart illustrates a pathway to guide differential diagnosis according to the prenatal findings. Main syndromes, key testing and specific genes are included. Targeted molecular testing should be offered to the couple in order to reach a diagnosis and assess the recurrence risk for future pregnancies.

Fetal akinesia: The application of clinical exome sequencing in cases with decreased fetal movement

OBJECTIVE

To determine monogenic syndromes in cases of fetal akinesia in order to understand the genetic aetiology.

STUDY DESIGN

Clinical trio exome sequencing (ES) was performed on DNA extracted from postnatal samples in 12 cases with fetal akinesia identified by prenatal ultrasound and a normal chromosomal micro-array analysis result. This test targets coding exons for 4200 clinically relevant disease-causing genes. The interpretation of variants was performed according to the guidelines of the American College of Medical Genetics.

RESULTS

A definite molecular diagnosis was achieved in six (50 %) of the 12 cases using clinical trio ES. In five cases, the pathogenic variants were located in known fetal-akinesia-associated genes. In one case, the underlying pathogenic variants were in known disease genes that had not been linked to fetal akinesia previously. Six pregnancies were terminated by the parents, and six pregnancies were continued to term.

CONCLUSION

Genetic defects leading to fetal akinesia were found in half of the study cases using clinical trio ES. This information will be useful in genetic counselling with regard to prognosis and risk of recurrence.

Prognostic significance of prenatal ultrasound in fetal arthrogryposis multiplex congenita

Purpose

Fetal arthrogryposis multiplex congenita (AMC) describes a heterogeneous disease entity characterized by multiple contractures affecting at least two different body areas. The aim of our study was to identify additional sonographic abnormalities in fetuses with AMC Type I–III associated with an unfavorable prognosis and to describe when those signs were first detected.

Methods

This retrospective study included 41 pregnancies of suspected AMC diagnosed 1999–2017 at our tertiary referral center. The affected pregnancies were divided into the 3 AMC subgroups; the time of detection and outcome were analyzed. Prenatal sonograms, pediatric charts, genetic tests, and autopsy reports were studied.

Results

Pregnancy outcome data were verifiable in 34 out of 41 cases; in 27 cases, AMC was confirmed. Hydrops was present in 50% of postnatally deceased fetuses, 53% of cases resulting in termination of pregnancy vs. 0% of the surviving 8 children. Absent stomach filling was found in 67% of the children with neonatal death. After subcategorization, the limb-involvement-only-group, 8% showed hydrops vs. 100% in system anomaly group vs. 70% in neuromuscular dysfunction cohort (p = 0.001). Scoliosis, nuchal edema, and absent stomach filling were significantly indicating for a neurological etiology.

Conclusion

In addition to disease-defining sonographic findings, those with prognostic significance were identified. Hydrops, nuchal edema, scoliosis and absent stomach filling were associated with unfavorable outcomes implicating a neuromuscular etiology. This knowledge can help to predict the further course of the disease and support patient counseling.

Genetic diagnosis and clinical evaluation of severe fetal akinesia syndrome

Objective

In this retrospective study, we describe the clinical course, ultrasound findings and genetic investigations of fetuses affected by fetal akinesia.

Materials and Methods

We enrolled 22 eukaryotic fetuses of 18 families, diagnosed with fetal akinesia between 2008 and 2016 at the Department of Obstetrics and Feto‐Maternal Medicine at the Medical University of Vienna. Routine genetic evaluation included karyotyping and chromosomal microarray analysis. Retrospectively, exome sequencing was performed in the index case of 11 families, if stored DNA was available. Confirmation analyses and genetic diagnosis of siblings were performed by using Sanger sequencing.

Results

Whole exome sequencing identified pathogenic variants of CNTN1, RYR1, NEB, GLDN, HRAS and TNNT3 in six cases of 11 families. In three of these families, the variants were confirmed in the respective sibling.

Conclusions

The present study demonstrates a high diagnostic yield of exome sequencing in fetuses affected by akinesia syndrome, especially if family history is positive. Still, in a large part the underlying genetic cause remained unknown, whereas precise clinical evaluation in combination with exome sequencing shows to be the best tool to find the disease causing variants.

Arthrogryposis Multiplex Congenita

Arthrogryposis multiplex congenita (AMC) is a complex, etiologically diverse, clinical descriptor identified in a variety of diagnoses characterized by multiple congenital joint contractures. The root cause of AMC is decreased fetal movement in-utero, whether resulting from maternal or pregnancy influences, nervous system pathology, or an underlying genetic abnormality. Prenatal diagnosis via ultrasonography can be challenging and may require additional imaging techniques or studies. After birth, these infants may require assistance breathing and feeding depending on the underlying diagnosis. Physical therapy and surgical intervention of the contractures are the mainstays of therapy, and outcomes can be good when intervention is provided in a timely manner. Those infants with syndromic causes of arthrogryposis are more likely to have poor outcomes; therefore, determining the underlying etiology for AMC is important as this can influence counseling regarding individual prognosis as well as future pregnancies. [Pediatr Ann. 2020;49(7):e299-e304.].

Congenital Cervical Spondyloptosis in the Neonate: A Prenatal Diagnosis

Congenital spine abnormalities are rare in the fetus and neonate. The illustrative case described in this article is unique as it depicts a neonate with prenatally diagnosed cervical spondyloptosis. Vertebral instability at any level of the spine, regardless of its etiology, is dangerous as it has the potential for neurologic involvement-making an early diagnosis and treatment paramount. Proper stabilization in the delivery room, transfer to the neonatal intensive care unit, and establishment of a multidisciplinary treatment plan are the mainstays of therapy. Diagnosis is usually obtained through computed tomography and magnetic resonance imaging performed during the fetal or, more commonly, neonatal period. Successful management is often accomplished in consultation with different pediatric subspecialists, particularly orthopedists and neurosurgeons. The definitive therapy is surgical intervention. Prognosis of this condition is dependent upon the severity of the malformation, time to stabilization, successful orthopedic and neurosurgical intervention, and proper adherence to follow-up. [Pediatr Ann. 2020;49(7):e313-e318.].

Myasthenia Gravis Can Have Consequences for Pregnancy and the Developing Child

Myasthenia gravis (MG) with onset below 50 years, thymic hyperplasia and acetylcholine receptor (AChR) antibodies is more common in females than in males. For a relatively large group of MG patients, pregnancy represents therefore an important question. The muscle weakness, the circulating autoantibodies, the hyperplastic thymus, the MG drug treatment, and any autoimmune comorbidity may all influence both mother and child health during pregnancy and also during breastfeeding in the postpartum period. Mother's MG remains stable in most patients during pregnancy. Pyridostigmine, prednisolone, and azathioprine are regarded as safe during pregnancy. Mycophenolate, methotrexate and cyclophosphamide are teratogenic and should not be used by women with the potential to become pregnant. Rituximab should not be given during the last few months before conception and not during pregnancy. Intravenous immunoglobulin and plasma exchange can be used for exacerbations or when need for intensified therapy. Pregnancies in MG women are usually without complications. Their fertility is near normal. Vaginal delivery is recommended. MG patients have an increased rate of Cesarean section, partly due to their muscle weakness and to avoid exhaustion, partly as a precaution that is often unnecessary. Around 10% of the newborn develop neonatal myasthenia during the first few days after birth. This is transient and usually mild with some sucking and swallowing difficulties. In rare cases, transplacental transfer of AChR antibodies leads to permanent muscle weakness in the child, and arthrogryposis with joint contractures. Repeated spontaneous abortions have been described due to AChR antibodies. MG women should always give birth at hospitals with experience in newborn intensive care. MG does not represent a reason for not having children, and the patients should be supported in their wish of becoming pregnant.

Orthopaedic care of the child with arthrogryposis: a 2020 overview

PURPOSE OF REVIEW

The orthopaedic treatment of children with arthrogryposis multiplex congenita has evolved steadily over the past two decades. Interrelated factors have spurred this on, including better appreciation of the functional potential of persons with arthrogryposis, development of newer procedures specific for the arthrogrypotic deformities, and outcomes studies that provide understanding of the overall capabilities of adults with arthrogryposis and follow-up to determine which treatments were beneficial and which were not. This article briefly sketches out of some of these advances and indicates areas that need further development.

RECENT FINDINGS

Outcome studies show that the majority of adults with arthrogryposis are ambulatory but less than half are fully independent. Adults frequently experience ongoing pain, particularly foot and back pain, limiting ambulation and standing. Advancements in the upper extremity treatment include improving elbow function, wrist repositioning, and improving thumb positioning. In the lower extremities, correction of hip and knee contractures leads to improved ambulatory potential, and treating clubfeet with serial casting decreases poor outcomes.

SUMMARY

Clinical evaluation, both physical examination and assessment of the patient's needs, are important in directing treatment in arthrogryposis. Further outcomes studies are needed to continue to refine procedures and define the appropriate candidates.

Collaborating to advance interdisciplinary care for individuals with arthrogryposis

This Special Issue on Interdisciplinary Care in Arthrogryposis highlights a collection of articles spanning topics in interdisciplinary care, genetic discoveries, and clinical research. An international group of clinicians and researchers from various backgrounds who attended the "3rd International Symposium on Arthrogryposis", held in Philadelphia, September 24-26, 2018, were invited to contribute to this issue. The goal of the 2018 Symposium and of this Special Issue is to provide momentum to advancing evidence-based practice and research in arthrogryposis, by working collaboratively with adults and families of children with arthrogryposis, clinicians, and researchers. The contents of this issue cover a range of topics from defining and classifying arthrogryposis multiplex congenita to early detection, rehabilitation, and orthopedic management, advances in genetic pathways, patient registries, autopsy guidelines, and research findings in the pediatric and adult populations with arthrogryposis. We hope that this issue provides an overview as well as new knowledge on arthrogryposis to generate more conversations at the international level, and advance care and research for individuals with arthrogryposis.