Fetal arthrogryposis multiplex congenita/fetal akinesia deformation sequence (FADS)-Aetiology, diagnosis, and management

The evolving genetic landscape of neuromuscular fetal akinesias

Fetal akinesia is a broad term used to describe absent (or reduced, fetal hypokinesia) fetal movements, and it can be detected as early as the first trimester. Depending on the developmental age of onset, anything that interferes or limits the normal in utero movement results in a range of deformations affecting multiple organs and organ systems. Arthrogryposis, also termed arthrogryposis multiplex congenita (AMC), is a definitive terminology for multiple congenital contractures, with two major subgroups; amyoplasia and distal arthrogryposis (DA). The spectrum includes fetal akinesia deformation sequence (FADS), lethal congenital contracture syndrome (LCCS), and multiple pterygium syndrome (MPS). Variants in more than >400 genes are known to cause AMC, and it is increasingly recognized that variants in genes encoding critical components (including ventral horn cell, peripheral nerve, neuromuscular junction, skeletal muscle) of the extended motor unit underlie ∼40% of presentations. With unbiased screening approaches, including sequencing of comprehensive disease gene panels, exomes and genomes, novel genes and phenotypic expansions associated with known human disease genes have been uncovered in the setting of fetal akinesia. Autosomal-recessive titinopathy is the most frequent genetic cause of AMC. Accurate genetic diagnosis is critical to genetic counseling and informing family planning. Around 50% remain undiagnosed following comprehensive prenatal, diagnostic or research screening. Comprehensive phenotyping and periodic reanalysis with appropriate genomic tools are valuable strategies when faced with initial inconclusive results. There are likely many novel causative genes still to identify, which will inform our understanding of the molecular pathways underlying early human development and in utero movement.

Perinatal genetic diagnostic yield in a population of fetuses with the phenotype arthrogryposis multiplex congenita: a cohort study 2007-2021

Arthrogryposis multiplex congenita (AMC) presents challenges for prenatal detection due to its heterogeneous etiology, onset, and phenotypical manifestations. This study aims to describe the genetic diagnostic yield in a population of fetuses with detailed phenotypic description over a 15-year period (2007-2021) at the Fetal Medicine Unit of Amsterdam UMC, the Netherlands. The fetal and neonatal phenotypes were classified into three clinical AMC Groups, with the exception that Groups 1 and 2 were combined in the prenatal classification. Group 1 involves limb involvement primarily, Group 2 includes musculoskeletal involvement plus other system anomalies, and Group 3 involves musculoskeletal involvement with central nervous system disability, lethality, fetal akinesia deformation sequence, and/or intellectual disability. The cohort consisted of 64 consecutive cases, 13 in Groups 1 + 2 and 51 in Group 3. Perinatal genetic testing occurred in all cases: prenatally in 56 of the 64 (88%), postnatally in 36 of the 64 (56%), and combined testing in 28 of the 64 cases (44%). The overall genetic diagnostic yield was 28% (18/64), and it increased over the 5-year period from 14% to 50%. Whole exome sequencing had the highest yield (41.7%). The yield per phenotype was 30.8% (4/13) for AMC Group 1 + 2 and 27.4% (14/51) for AMC Group 3. Detailed fetal phenotyping and perinatal genetic testing in all cases showed improved diagnostic yield over time, likely due to the introduction of Next-generation sequencing-based tests. The availability of stored DNA will be beneficial for future investigations since further improvements in genetic testing possibilities are expected.

Maternal, fetal and neonatal outcomes among pregnant women with arthrogryposis multiplex congenita: a scoping review

BACKGROUND

The rarity of pregnancies in women with arthrogryposis multiplex congenita (AMC) could lead to healthcare providers having limited exposure to these cases. Consequently, they may be less familiar with the possibilities and challenges associated with pregnancies in women affected by AMC. AMC is an umbrella term for a disorder with multiple contractures at birth, having a broad spectrum of causes, onset and severity of expression. A clinical classification describing the phenotype is Group 1 with primary limb involvement, Group 2 with musculoskeletal involvement plus other system anomalies, and Group 3 with musculoskeletal involvement plus central nervous system dysfunction and/or intellectual disability. A scoping review was conducted to review available literature on documented cases of pregnancies in women with AMC, with the following aims: (1) to outline the maternal, fetal and neonatal outcomes; (2) to describe AMC stability during and after pregnancy (worsening of symptoms due to contractures, increased muscle weakness, pain or lung involvement); and (3) to summarize counselling aspects during pregnancy for expecting mothers who have AMC.

RESULTS

This scoping review included 27 manuscripts reporting on 43 women with 82 pregnancies, of whom 18 in Group 1, 20 in Group 2, 2 in Group 3, and 3 with an unknown type. Details on pregnancy-related outcomes could be depicted from 26 of the 43 women concerning 31 pregnancies. Among these pregnancies, 74% (23/31) had a cesarean section delivery, of which 74% (17/23) were elective. Children were born preterm before week 37 in 7 of 31 pregnancies (22%). A birth weight below the 10th percentile was seen in 6 of the 24 (25%) with a reported birth weight. The course of the pregnancy was uneventful in 16 of the 26 women (62%). Pregnancy had a limited negative influence on AMC stability except for three cases with a transient worsening of lung function.

CONCLUSIONS

Gathering the information of the case histories revealed that the majority of the reported women had Distal Arthrogryposis with stable AMC during pregnancy and after delivery. The risk to have a cesarean section, preterm labour or a small for gestational age child is higher in this group than in the general population. Insights obtained by this review emphasized to offer (pre)pregnancy counselling and care by a multidisciplinary team tailored to the women's type of AMC, to ensure optimal preparation for both obstetric, genetic, neurologic, pulmonary and anesthetic care during pregnancy, delivery and postpartum period.

The First Known Case Report of a Novel Homozygous Nonsense Variant in the OSBPL9 Gene Associated With Fetal Cerebral Ventriculomegaly, Cerebellar Hypoplasia, and Arthrogryposis Multiplex

Oxysterol-binding protein-like protein 9 (OSBPL9) is a member of a large eukaryotic gene lipid transport protein family that mediates the exchange of sterols and phospholipids between the trans-Golgi network and the endoplasmic reticulum. Denovo missense mutations in the OSBPL9 gene have been previously reported to be associated with intellectual disability. Herein, we report for the first time, to the best of our knowledge, a novel homozygous nonsense variant in the OSBPL9 gene in a consanguineous family with two fetuses with cerebral ventriculomegaly, cerebellar hypoplasia, and arthrogryposis multiplex. Whole exome sequencing and homozygosity mapping by chromosomal microarray identified one fetus to be homozygous for a novel nonsense variant chr1-51760720C>CAAT or c.615_616insTAA or p.Pro206*. Exome sequencing identified the asymptomatic parents as carriers for the same variant, indicating an autosomal recessive inheritance pattern. A review of medical literature using databases such as PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), and Google Scholar did not reveal any case with the OSBPL9 variant and fetal malformations such as ventriculomegaly, cerebellar hypoplasia, and arthrogryposis multiplex. A protein network analysis using the STRING (Search Tool for Retrieval of Interacting Genes/Proteins) database showed close interactions between the OSPBPL9, OSBP, PI4K2A, PIP5K1C, PI4KA, CERT1, EXOSC3, RARS2, VRK1, and TSEN54 genes but no interactions with the L1CAM, KIDINS220, and KIAA1109 genes. These proteins are important for the metabolism of sphingomyelin, sterol, and lipids such as phosphatidylinositol and ceramide in the cell. Mutations in these proteins are known to cause related genetic disorders, which include structural brain abnormalities, fetal arthrogryposis, and intellectual disability as a phenotype. This is the first known report of a homozygous variant in the OSBPL9 gene in a recessive inheritance pattern, and the first report of association with a fetal anomaly phenotype. Previously, only two cases with an OSBPL9 gene variant have been documented in the literature, showing a sporadic autosomal dominant inheritance pattern. Thus, this case report expands the phenotype of OSBPL9 gene-related human disease. This case report will aid clinical diagnosis, genetic counseling, and preventive strategies such as prenatal diagnosis and/or preimplantation genetic diagnosis in families affected with OSBPL9 gene variants. The limitation of this study is the lack of RNA, protein, cellular, or animal model studies or functional studies to confirm this association.

The First Case Report of a Homozygous Consensus Acceptor Splice Variant in the NUP214 Gene Associated With Fetal Hydrops and Arthrogryposis Multiplex

The NUP214 gene encodes a nuclear pore complex protein (nucleoporin, 214 kilodaltons) which plays a critical role in messenger RNA export to the cytoplasm and import of substrates from the cytoplasm. Biallelic mutations in the NUP214 gene have been associated with susceptibility to acute infection-induced encephalopathy type 9 (ILAE9) (Online Mendelian Inheritance in Man (OMIM), 114350), an autosomal recessive disorder. Herein, we describe for the first time, a fetus with hydrops and arthrogryposis multiplex with a homozygous novel consensus splice site variant in the NUP214 gene, chr9:g.131127522A>G or c.46-2A>G (transcript ID NM_005085.4). Parents were heterozygous for the same variant. Mutations in either of 83 genes have been previously published to cause fetal arthrogryposis multiplex but mutations in NUP214 have not been previously reported as per our search in the available medical literature (PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online) and Google Scholar). STRING (Search Tool for Retrieval of Interacting Genes/Proteins) analysis showed close interactions between NUP214 and the other proteins GLE1, NUP88, NEK9, and THOC2. Thus, this case report expands the phenotype of NUP214 gene-related human disease.

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.

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.

WHAT THIS PAPER ADDS

The common data elements (CDEs) for arthrogryposis multiplex congenita include 321 data elements from perinatal period to adulthood. A universal governance structure, partner-specific operating protocols, and sustainability plans will facilitate multi-institutional implementation of CDEs. Inconsistent electronic infrastructure, different terminologies for databases, and feasibility issues are the main barriers for international implementation of CDEs.

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.

Advancing fetal diagnosis and prognostication using comprehensive prenatal phenotyping and genetic testing

Prenatal diagnoses of congenital malformations have increased significantly in recent years with use of high-resolution prenatal imaging. Despite more precise radiological diagnoses, discussions with expectant parents remain challenging because congenital malformations are associated with a wide spectrum of outcomes. Comprehensive prenatal genetic testing has become an essential tool that improves the accuracy of prognostication. Testing strategies include chromosomal microarray, exome sequencing, and genome sequencing. The diagnostic yield varies depending on the specific malformations, severity of the abnormalities, and multi-organ involvement. The utility of prenatal genetic diagnosis includes increased diagnostic clarity for clinicians and families, informed pregnancy decision-making, neonatal care planning, and reproductive planning. Turnaround time for results of comprehensive genetic testing remains a barrier, especially for parents that are decision-making, although this has improved over time. Uncertainty inherent to many genetic testing results is a challenge. Appropriate genetic counseling is essential for parents to understand the diagnosis and prognosis and to make informed decisions. Recent research has investigated the yield of exome or genome sequencing in structurally normal fetuses, both with non-invasive screening methods and invasive diagnostic testing; the prenatal diagnostic community must evaluate and analyze the significant ethical considerations associated with this practice prior to generalizing its use. IMPACT: Reviews available genetic testing options during the prenatal period in detail. Discusses the impact of prenatal genetic testing on care using case-based examples. Consolidates the current literature on the yield of genetic testing for prenatal diagnosis of congenital malformations.

Prenatal diagnosis (or lack thereof) of arthrogryposis multiplex congenita and its impact on the perinatal experience of parents: A retrospective survey

OBJECTIVE

To examine parental experiences during pregnancies affected by Arthrogryposis Multiplex Congenita (AMC) by identifying commonalities, risk factors, and areas for improvement in detection rates, care protocols, and patient experience.

STUDY DESIGN

An online survey was distributed via AMC support groups on Facebook. Topics included demographics, risk factors, parental recall of sonographic findings, delivery characteristics and neonatal findings. Responses were divided into antenatally detected cases (ADCs) and postnatally detected cases (PDCs). Quantitative responses were analyzed with the Fisher exact test. Qualitative data were analyzed with thematic analysis.

RESULTS

The antenatal detection rate of arthrogryposis was 37%. Decreased fetal movement was reported by 53% and early bleeding by 21%. Sonographic findings in ADCs included clubfoot (83%), clenched hand (51%), decreased fetal movement (50%), elbow contracture (51%), and knee contracture (46%). Among ADCs, 29% delivered vaginally and 71% delivered by cesarean versus PDCs (44% vaginal, 56% cesarean). Neonatal intensive care unit admission rate was 63%. Bone fracture occurred in 9%. Detection led to a planned change in delivery mode in 33% and location in 50%. Among ADCs, 17% felt their concerns were not adequately addressed versus 43% of PDCs.

CONCLUSIONS

Antenatal detection of arthrogryposis was low. We propose enhanced screening criteria to aid prenatal diagnosis and promote utilization of more robust practice guidelines.

Variants in DOK7 results in fetal akinesia deformation sequence: A case report and review of literature

We report the third case of FADS due to biallelic DOK7 variants, which further strengthens the association of DOK7 with this lethal phenotype and lack of genotype phenotype correlation.

A rare case of arthrogryposis multiplex congenita in a 2-year-old boy case report

Arthrogryposis multiplex congenita (AMC) is an uncommon condition present from birth that is marked by a combination of weakened muscles and multiple joint contractures. We present a case of a 2-year-old boy with AMC, who was born to consanguineous parents in Saudi Arabia. He presented with musculoskeletal abnormalities of all four limbs, including symmetric contractures in multiple joints of the body, bilateral developmental dysplasia of the hip, and vertical talus. Dysmorphic features included low-set ears, chin recession, triangular face, and nevus flammeus on the face. The child also had lactose intolerance, gastritis, inguinal hernia, and right-sided undescended testis. Surgical interventions were planned after a multidisciplinary team discussion. This case report highlights the good prognosis of AMC with all four-limb involvement and the importance of a thorough physical examination and a multidisciplinary approach to the diagnosis and management of AMC.

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.

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.

Prenatal diagnosis of SMPD4 loss - A neurodevelopmental disorder with microcephaly, arthrogryposis and structural brain anomalies

SMPD4 loss is a rare neurodevelopmental disorder that leads to severe mental and physical disability and early death in infancy. Most cases of this genetic condition have been diagnosed postnatally. This article focuses on the prenatal findings of affected fetuses. The phenotypes can include growth restriction, arthrogryposis (clenched hands, foot deformity), as well as cerebral abnormalities (simplified gyral pattern/lissencephaly, cerebellar hypoplasia, corpus callosum deformity). SMPD4 loss is detectable via exome sequencing. Here, two fetuses displayed a homozygotic pathogen variant in the SMPD4 gene, encoding for the enzyme Sphingomyelinase-4. Both parents were heterozygous carriers of the pathogenic variant. On detection of the above mentioned signs exome sequencing is indicated, with focus on the SMPD4 gene.

Fetal akinesia deformation sequence syndrome associated with recessive TTN variants

Arthrogryposis multiplex congenita (AMC) [also known as multiple joints contracture or Fetal Akinesia Deformation Sequence (FADS)] is etiologically a heterogeneous condition with an estimated incidence of approximately 1 in 3000 live births and much higher incidence when prenatally diagnosed cases are included. The condition can be acquired or secondary to fetal exposures and can also be caused by a variety of single-gene disorders affecting the brain, spinal cord, peripheral nerves, neuromuscular junction, muscle, and a variety of disorders affecting the connective tissues (Niles et al., Prenatal Diagnosis, 2019; 39:720-731). The introduction of next-generation gene sequencing uncovered many genes and causative variants of AMC but also identified genes that cause both dominant and recessive inherited conditions with the variability of clinical manifestations depending on the genes and variants. Molecular diagnosis in these cases is not only important for prognostication but also for the determination of recurrence risk and for providing reproductive options including preimplantation and prenatal diagnosis. TTN, the largest known gene in the human genome, has been known to be associated with autosomal dominant dilated cardiomyopathy. However, homozygote and compound heterozygote pathogenic variants with recessive inheritance have rarely been reported. We report the effect of recessive variants located within the fetal IC and/or N2BA isoforms in association with severe FADS in three families. All parents were healthy obligate carriers and none of them had cardiac or skeletal muscle abnormalities. This report solidifies FADS as an alternative phenotypic presentation associated with homozygote/compound heterozygous pathogenic variants in the TTN.

Clinical and Pathologic Features of Congenital Myasthenic Syndromes Caused by 35 Genes-A Comprehensive Review

Congenital myasthenic syndromes (CMS) are a heterogeneous group of disorders characterized by impaired neuromuscular signal transmission due to germline pathogenic variants in genes expressed at the neuromuscular junction (NMJ). A total of 35 genes have been reported in CMS (AGRN, ALG14, ALG2, CHAT, CHD8, CHRNA1, CHRNB1, CHRND, CHRNE, CHRNG, COL13A1, COLQ, DOK7, DPAGT1, GFPT1, GMPPB, LAMA5, LAMB2, LRP4, MUSK, MYO9A, PLEC, PREPL, PURA, RAPSN, RPH3A, SCN4A, SLC18A3, SLC25A1, SLC5A7, SNAP25, SYT2, TOR1AIP1, UNC13A, VAMP1). The 35 genes can be classified into 14 groups according to the pathomechanical, clinical, and therapeutic features of CMS patients. Measurement of compound muscle action potentials elicited by repetitive nerve stimulation is required to diagnose CMS. Clinical and electrophysiological features are not sufficient to identify a defective molecule, and genetic studies are always required for accurate diagnosis. From a pharmacological point of view, cholinesterase inhibitors are effective in most groups of CMS, but are contraindicated in some groups of CMS. Similarly, ephedrine, salbutamol (albuterol), amifampridine are effective in most but not all groups of CMS. This review extensively covers pathomechanical and clinical features of CMS by citing 442 relevant articles.

Novel Arthrogryposis Multiplex Congenita Presentation in a Newborn With Pierpont Syndrome

Pierpont syndrome is a rare and recently described multiple congenital anomaly syndrome, classically characterized by global developmental delay, distinctive facial dysmorphic features, and abnormal fat distribution in distal limbs. Only few cases were previously documented. We report a case of a term male neonate admitted to the neonatal intensive care unit because of feeding difficulties. Intrauterine growth restriction, microcephaly, and bilateral equinovarus foot were diagnosed in the second trimester, and prenatal array comparative genomic hybridization showed no abnormality. Physical examination revealed bilateral flexion deformities of wrists, elbows, knees and clubfoot, large hands and feet, deep palmar and plantar grooves, and calcaneo-plantar fat pads. Craniofacial dysmorphism, axial hypotonia, and hypoactivity were also observed. Due to the presence of congenital and non-progressive joint contractures, arthrogryposis multiplex congenita (AMC) was considered. A comprehensive diagnostic workup, including a Next Generation Sequencing target panel, was performed but did not establish a diagnosis. The clinical exome identified an heterozygous pathogenic variant in the TBL1XR1 gene (NM_001321194.1: c.1337A>G, p.[Tyr446Cys]), allowing Pierpont syndrome diagnosis. Our case stands out for reporting the novel AMC presentation in a Pierpont syndrome newborn. The broader and precocious genetic testing proved to be an essential clarifying diagnostic tool. Our patient supports the relation between the p.Tyr446Cys sequence variant in TBL1XR1 gene with this rare syndrome, reinforcing its association with a distinctive and recognizable phenotype, as well as expanding its clinical features to include AMC.

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.

Lethal Congenital Contracture Syndrome 11: A Case Report and Literature Review

Lethal congenital contracture syndrome 11 (LCCS11) is caused by homozygous or compound heterozygous variants in the GLDN gene on chromosome 15q21. GLDN encodes gliomedin, a protein required for the formation of the nodes of Ranvier and development of the human peripheral nervous system. We report a fetus with ultrasound alterations detected at 28 weeks of gestation. The fetus exhibited hydrops, short long bones, fixed limb joints, absent fetal movements, and polyhydramnios. The pregnancy was terminated and postmortem studies confirmed the prenatal findings: distal arthrogryposis, fetal growth restriction, pulmonary hypoplasia, and retrognathia. The fetus had a normal chromosomal microarray analysis. Exome sequencing revealed two novel compound heterozygous variants in the GLDN associated with LCCS11. This manuscript reports this case and performs a literature review of all published LCCS11 cases.

Diagnostic Value and Application of Prenatal MRI and Ultrasound in Fetal Cleft Lip and Palate

Objective

The purpose was to explore the diagnostic value and application of prenatal magnetic resonance imaging (MRI) and ultrasound (US) in fetal cleft lip and palate.

Methods

From January 2018 to December 2019, 39 pregnant women without normal fetal maxillofacial structure or with fetal maxillofacial deformity under US examination in our hospital were selected as the study subjects. Not knowing the clinical data of the pregnant women, MRI and US physicians performed diagnostic analysis on the MRI or US images of all the study subjects and analyzed the results of prenatal MRI and US diagnosis and postpartum follow-up to compare the diagnostic efficacy and confidence of MRI and US.

Results

The follow-up found that there were 20 cases of cleft lip, 15 cases of cheilopalatognathus, 3 cases of cleft palate, and 1 case of unilateral cleft lip with alveolar cleft, with a total of 39 cases having cleft lip and palate deformity. MRI and US had the same efficacy in the diagnosis of cleft lip. As for cleft palates, the diagnostic accuracy of MRI (94.87%) was significantly better than that of US (48.72%, P < 0.001). The diagnostic confidence of fetal cleft lip and palate by MRI (89.73%) was significantly better than that of US (43.59%, P < 0.001). The AUC of US (0.597) was significantly less than that of MRI (0.940), indicating that the diagnostic accuracy of US was not as good as that of MRI (P < 0.05). The sensitivity and 1 − specificity of MRI were significantly higher than those of US.

Conclusion

MRI is more accurate than US in the diagnosis of fetal cleft lip and palate, and MRI can be the preferred method for prenatal detection of cleft lip and palate, thus providing more accurate opinions and information for perinatal pregnant women.

Bioinformatics Analysis and Experimental Verification Identify Downregulation of COL27A1 in Poor Segmental Congenital Scoliosis

BACKGROUND

Congenital scoliosis (CS) represents the congenital defect disease, and poor segmental congenital scoliosis (PSCS) represents one of its types. Delayed intervention can result in disability and paralysis. In this study, we would identify the core biomarkers for PSCS progression through bioinformatics analysis combined with experimental verification.

METHODS

This work obtained the GSE11854 expression dataset associated with somite formation in the GEO database, which covers data of 13 samples. Thereafter, we utilized the edgeR of the R package to obtain DEGs in this dataset. Then, GO annotation, KEGG analyses, and DO annotation of DEGs were performed by "clusterProfiler" of the R package. This study performed LASSO regression for screening the optimal predicting factors for somite formation. Through RNA sequencing based on peripheral blood samples from healthy donors and PSCS cases, we obtained the RNA expression patterns and screen out DEGs using the R package DESeq2. The present work analyzed COL27A1 expression in PSCS patients by the RT-PCR assay.

RESULTS

A total of 443 genes from the GSE11854 dataset were identified as DEGs, which were involved in BP associated with DNA replication, CC associated with chromosomal region, and MF associated with ATPase activity. These DEGs were primarily enriched in the TGF-β signaling pathway and spinal deformity. Further, LASSO regression suggested that 9 DEGs acted as the signature markers for somite formation. We discovered altogether 162 DEGs in PSCS patients, which were involved in BP associated with cardiac myofibril assembly and MF associated with structural constituent of muscle. However, these 162 DEGs were not significantly correlated with any pathways. Finally, COL27A1 was identified as the only intersected gene between the best predictors for somite formation and PSCS-related DEGs, which was significantly downregulated in PSCS patients.

CONCLUSION

This work sheds novel lights on DEGs related to the PSCS pathogenic mechanism, and COL27A1 is the possible therapeutic target for PSCS. Findings in this work may contribute to developing therapeutic strategies for PSCS.

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.

Care of the critically ill neonate with hypoxemic respiratory failure and acute pulmonary hypertension: framework for practice based on consensus opinion of neonatal hemodynamics working group

Circulatory transition after birth presents a critical period whereby the pulmonary vascular bed and right ventricle must adapt to rapidly changing loading conditions. Failure of postnatal transition may present as hypoxemic respiratory failure, with disordered pulmonary and systemic blood flow. In this review, we present the biological and clinical contributors to pathophysiology and present a management framework.

SCN1A Mutation-Beyond Dravet Syndrome: A Systematic Review and Narrative Synthesis

Background: SCN1A is one of the most common epilepsy genes. About 80% of SCN1A gene mutations cause Dravet syndrome (DS), which is a severe and catastrophic epileptic encephalopathy. More than 1,800 mutations have been identified in SCN1A. Although it is known that SCN1A is the main cause of DS and genetic epilepsy with febrile seizures plus (GEFS+), there is a dearth of information on the other related diseases caused by mutations of SCN1A. Objective: The aim of this study is to systematically review the literature associated with SCN1A and other non-DS-related disorders. Methods: We searched PubMed and SCOPUS for all the published cases related to gene mutations of SCN1A until October 20, 2021. The results reported by each study were summarized narratively. Results: The PubMed and SCOPUS search yielded 2,889 items. A total of 453 studies published between 2005 and 2020 met the final inclusion criteria. Overall, 303 studies on DS, 93 on GEFS+, three on Doose syndrome, nine on the epilepsy of infancy with migrating focal seizures (EIMFS), six on the West syndrome, two on the Lennox-Gastaut syndrome (LGS), one on the Rett syndrome, seven on the nonsyndromic epileptic encephalopathy (NEE), 19 on hemiplegia migraine, six on autism spectrum disorder (ASD), two on nonepileptic SCN1A-related sudden deaths, and two on the arthrogryposis multiplex congenital were included. Conclusion: Aside from DS, SCN1A also causes other epileptic encephalopathies, such as GEFS+, Doose syndrome, EIMFS, West syndrome, LGS, Rett syndrome, and NEE. In addition to epilepsy, hemiplegic migraine, ASD, sudden death, and arthrogryposis multiplex congenital can also be caused by mutations of SCN1A.

The efficacy and safety of Xuefu Zhuyu Decoction combined with Mifepristone in the treatment of uterine leiomyoma: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Uterine leiomyoma (UL) is a common severe gynecological issue. In China, Xuefu Zhuyu Decoction (XFZYD), combined with Mifepristone, is widely used in the treatment of UL. However, their combined effectiveness and safety for this purpose have not yet been explored.

AIM OF THE STUDY

This systematic review aims to evaluate the effectiveness and safety of XFZYD combined with Mifepristone as a method of treatment for UL.

MATERIALS AND METHODS

We searched the following 7 databases: 3 English medical databases (PubMed, EMBASE, Cochrane Library), and 4 Chinese medical databases (Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure (CNKI), Chinese Scientific Journal Database (VIP), and the Wanfang database). The primary outcome was the effect of XFZYD combined with Mifepristone on the effective rate, uterine leiomyoma volume (ULV), and uterine volume (UV) of uterine leiomyoma. Bias risk was assessed using the Cochrane risk of bias tool. The software RevMan5 was used to evaluate the quality of the included studies and process the data.

RESULTS

The 11 studies included in this systematic review were all undertaken in China, with a total of 902 participants. The meta-analysis of XFZYD combined with Mifepristone compared with Mifepristone alone showed that the effective rate (RR 1.20, 95% confidence interval (CI): 1.14-1.27, P < 0.00001), ULV (SMD -1.60, 95% CI: 2.11 to -1.08, P < 0.00001), and UV (SMD -1.65, 95% CI: 1.85 to -1.44, P < 0.00001) in the primary outcomes, and estradiol (E2) (MD -51.81, 95% CI: 69.68 to -33.94, P < 0.00001), luteinizing hormone (LH) (MD -3.09, 95% CI: 3.58 to -2.60, P < 0.00001), follicle stimulating hormone (FSH) (MD -1.09, 95% CI: 1.86 to -0.31, P = 0.006), progesterone (P) (MD -3.55, 95% CI: 4.54 to -2.55, P < 0.00001), and adverse events (RR 0.55, 95% CI: 0.34-0.89), P = 0.01) in the secondary outcomes were significantly reduced, and the data were statistically significant. The subgroups of ULV, E2, and FSH showed that the treatment time might not have been the heterogeneous source of ULV and FSH, but was the heterogeneous source of E2. Sensitivity analysis was carried out on the 3 outcome indicators, and the results were relatively stable after excluding one reference for each indicator.

CONCLUSION

There is some encouraging evidence that the combination of XFZYD and Mifepristone can benefit patients by treating UL. However, because of research shortcomings such as lacking allocation concealment and blindness, this study's results should be treated with caution. In order to verify the advantages of this method, it is necessary to carry out further large-scale randomized controlled trials.

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.

Application of Combined Ultrasound and Maternal Serum Biochemical Indexes in the Detection of Fetal Structural Abnormalities and Chromosomal Abnormalities

By exploring different prenatal diagnosis indications of fetal chromosomal abnormalities, it can provide a theoretical basis and reference value for clinical consultation of pregnant women with similar high-risk factors. In this paper, 1800 pregnant women undergoing amniotic fluid aspiration chromosomal examination in the prenatal diagnosis center were selected as the object of this study. Amniocentesis, fetal cell culture, and karyotype analysis were performed on pregnant women who were 14-20 weeks pregnant and had signed an informed consent. After amniocentesis fetal chromosome analysis, the type of fetal chromosomal abnormality was determined, and the detection rate of chromosomal abnormality was statistically described. Chi-square test was used for comparison between groups, P < 0.05. This study shows that the use of ultrasound screening combined with maternal serum indicators is effective in screening fetal structural abnormalities and chromosomal abnormalities in early pregnancy, and significantly improves the detection rate of chromosomal abnormalities. The detection of fetal structural malformations is also very high, but it should be combined with ultrasound screening of mid-to-late pregnancy. The tricuspid regurgitation and umbilical vein a-wave reversal in the soft ultrasound index can be used as predictors of fetal congenital heart disease in early pregnancy.

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.

Deformations associated with arthrogryposis

Fetal movement is essential to normal human development. If the fetus does not move for whatever reason, then multiple organs and organ systems develop secondary and tertiary effects not normally present. Most of these are deformations with secondary structural damage.

The efficacy and safety of Xuefu Zhuyu Decoction combined Mifepristone in the treatment of Uterine leiomyoma: A protocol systematic review and meta-analysis

BACKGROUND

Uterine leiomyoma (UL) is a common severe gynecological issue. In China, Xuefu Zhuyu Decoction (XFZYD), combined with Mifepristone, is widely used in the treatment of UL. However, their combined effectiveness and safety for this purpose have not yet been explored.

OBJECTIVE

This systematic review aims to evaluate the effectiveness and safety of XFZYD combined with Mifepristone as a method of treatment for UL.

METHODS

We searched the following 7 databases: 3 English medical databases (PubMed, EMBASE, Cochrane Library), and 4 Chinese medical databases (Chinese Biomedical Literature Database (CBM), Chinese National Knowledge Infrastructure (CNKI), Chinese Scientific Journal Database (VIP), and the Wanfang database). The primary outcome was the effect of XFZYD combined with Mifepristone on the effective rate, uterine leiomyoma volume (ULV), and uterine volume (UV) of uterine leiomyoma. Bias risk was assessed using the Cochrane risk of bias tool. The software RevMan5 was used to evaluate the quality of the included studies and process the data.

RESULTS

This study will evaluate the efficacy and safety of XFZYD combined with Mifepristone in the treatment of uterine fibroids by evaluating the effective rate, Uterine Leiomyoma volume, and uterine volume, the incidence of estradiol, luteinizing hormone, and other indicators.

CONCLUSION

This study will provide reliable evidence-based evidence for Xuefu Zhuyu Decoction Combined with Mifepristone in the treatment of uterine fibroids.

ETHICS AND DISSEMINATION

Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval will not be required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/YADN3.

Locomotion and Topographical Working Memory in Children With Myelomeningocele and Arthrogryposis Multiplex Congenita

Background: In children with myelomeningocele (MMC) and arthrogryposis multiplex congenital (AMC), adequate rehabilitation measures are accessible with the goal of attaining the utmost motor development. However, there is a lack of knowledge as to how children develop navigation utilizing their locomotion abilities. The aim of the present study was to explore topographic working memory in children with MMC and AMC. Methods: For this purpose, we assessed 41 children with MMC and AMC, assigned an ambulation group, and 120 typical developing (TD) children, with mean ages of 11.9, 10.6, and 9.9 years, respectively. All groups performed a topographic working memory test while moving in a walking space and a visuospatial working memory test in a reaching space. Children with MMC and AMC also performed a test to measure their ability to reason on visuospatial material, Raven's Coloured Progressive Matrices. Results: The topographic working memory span was shorter in the MMC group than in the TD group. In general, all ambulation groups had a shorter topographic working memory span than the TD group. The visuospatial working memory span was shorter in the non-ambulation group than in the TD group. Scores from the visuospatial reasoning test were lower in the non-ambulation group than in the community ambulation group. Conclusions: Even though a higher cognitive score was found in the community ambulation group than in the non-ambulation group, topographic working memory was affected similarly in both groups. Including children who develop community ambulation in therapy programs containing aspects of navigation may gain even children with low levels of MMC and AMC. These results evidenced the importance of motor development and navigational experience gained through direct exploration of the environment on topographic memory.

Making and shaping endochondral and intramembranous bones

Skeletal elements have a diverse range of shapes and sizes specialized to their various roles including protecting internal organs, locomotion, feeding, hearing, and vocalization. The precise positioning, size, and shape of skeletal elements is therefore critical for their function. During embryonic development, bone forms by endochondral or intramembranous ossification and can arise from the paraxial and lateral plate mesoderm or neural crest. This review describes inductive mechanisms to position and pattern bones within the developing embryo, compares and contrasts the intrinsic vs extrinsic mechanisms of endochondral and intramembranous skeletal development, and details known cellular processes that precisely determine skeletal shape and size. Key cellular mechanisms are employed at distinct stages of ossification, many of which occur in response to mechanical cues (eg, joint formation) or preempting future load‐bearing requirements. Rapid shape changes occur during cellular condensation and template establishment. Specialized cellular behaviors, such as chondrocyte hypertrophy in endochondral bone and secondary cartilage on intramembranous bones, also dramatically change template shape. Once ossification is complete, bone shape undergoes functional adaptation through (re)modeling. We also highlight how alterations in these cellular processes contribute to evolutionary change and how differences in the embryonic origin of bones can influence postnatal bone repair.

Compares and contrasts Endochondral and intramembranous bone development

Reviews embryonic origins of different bones

Describes the cellular and molecular mechanisms of positioning skeletal elements.

Describes mechanisms of skeletal growth with a focus on the generation of skeletal shape

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.

Obstetric complications in pregnancies with life-limiting malformations

PURPOSE OF REVIEW

The implementation of palliative care at birth has led to a significant rise in the number of couples who choose to continue with pregnancies complicated by life-limiting malformations (LLMs). Prenatal counselling and appropriate antenatal/perinatal management in these cases are poorly studied and may pose significant challenges. The purpose of this review is to outline specific obstetric risks and to suggest management for mothers who choose to continue with pregnancies with the most common LLMs.

RECENT FINDINGS

In pregnancies complicated by LLMs where parents opt for expectant management, clinicians should respect parental wishes, whilst openly sharing potential serious maternal medical risks specific for the identified abnormalities. The focus of both antenatal and perinatal care should be maternal wellbeing rather than foetal survival. Follow-up ultrasound examinations and maternal surveillance should be aimed at achieving timely diagnosis and effective management of obstetric complications. A clear perinatal plan, agreed with the couples by a multi-disciplinary team including a foetal medicine specialist, a neonatologist and a geneticist, is crucial to reduce maternal morbidity.

SUMMARY

This review provides a useful framework for clinicians who face the challenges of counselling and managing cases complicated by LLMs where parents opt for pregnancy continuation.

Ultrasonographic evidence of persistent hyperextension of the fetal neck: is it a true sign? A diagnostic and prognostic challenge

OBJECTIVE

The purpose of this study was to evaluate the clinical evolution, structural anomalies associated and neonatal outcomes of fetal neck hyperextension in two cases with prenatal ultrasound diagnosis in two different gestational ages.

METHODS

In 2019, two cases of fetal hyperextension came to our attention. Follow-up information was obtained from hospital medical records and obstetrical care providers.

RESULTS

Two woman were investigated in our institution for the presence of fetal abnormalities in the II and III trimester, respectively. In both cases, fetal attitude presented persistent fetal neck hyperextension. One of the two fetuses had a mild ventriculomegaly and suspected for micrognathia. Both had an amniotic fluid increase. One of two had no movement in the lower and upper limbs in ultrasound scans associated with club foot and suspected scoliosis. Both were born by cesarean section with pretty different prognosis: one healthy baby had a retarded psychomotor development and the other one died after 6 months. A precise diagnosis was possible only in one case.

CONCLUSION

The early identification of a fetus with persistent hyperextension of the fetal head should require a detailed ultrasound exam for structural abnormalities and a careful prenatal counseling due to possible postnatal outcome.

Prenatal delineation of a distinct lethal fetal syndrome caused by a homozygous truncating KIDINS220 variant

Kinase D-interacting substrate of 220 kDa (KIDINS220) is a transmembrane protein playing integral role in growth mediating pathways in the nervous and cardiovascular systems. KIDINS220 heterozygous truncating variants that affect the protein's C-terminus have been associated with a phenotype, so far described only in few unrelated children, including spastic paraplegia, intellectual disability, nystagmus, and obesity. More recently, a homozygous, more N-terminal truncating variant in KIDINS220 gene was suggested to be associated with enlarged cerebral ventricles and limb contractures in three fetuses from a consanguineous family. We confirm the latter finding by presenting the first detailed prenatal identification of a fetal phenotype associated with novel homozygous deleterious frameshift variant in KIDINS220 gene in a consanguineous healthy Egyptian couple. History of unexplained seven miscarriages and a similar stillbirth were recorded. Prenatal ultrasonography revealed limb contractions and ventriculomegaly; in addition to previously unreported cerebellar anomalies, cardiac anomalies and hydrops fetalis. These findings represent an expansion of clinical and molecular spectrum associated with KIDINS220 variants and broaden our understanding of genotype-phenotype relationships in lethal congenital contractures syndromes and associated severe abnormal embryological development. More generally, our study adds KIDINS220 to the rare group of genes which may cause disease by either of two distinct mutational mechanisms.

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.

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.

Biallelic c.1263dupC in DOK7 results in fetal akinesia deformation sequence

Fetal akinesia deformation sequence (FADS) is a clinically and genetically heterogeneous condition. Pathogenic variants in DOK7 are known to cause myasthenic syndrome, congenital, 10 (MIM#254300) and, rarely (reported in a single family) lethal FADS. Herein, we describe a biallelic variant c.1263dupC in DOK7, known to cause congenital myasthenic syndrome 10, causing lethal FADS in a consanguineous family. The present report illustrates wide phenotypic variability caused by biallelic pathogenic variants in DOK7. We also describe the second family with FADS due to pathogenic variants in DOK7.