Bilateral Sprengel Deformities, Mirror Movements Synkinesis, and Arthrogryposis Multiplex Congenita: A Novel Combination.

Introduction: Bilateral Sprengel deformities, mirror movements synkinesis, and arthrogryposis are described in different combinations in various syndromes but never together. Case Report: We present a 12-year-old girl who presented with bilateral shoulder deformities and difficulty in coordination while writing. On examination, she was noted to have bilateral Sprengel deformities with flexion contractures of upper-limb joints and mirror movements of both upper and lower-limb joints. Conclusion: In the light of relevant literature, we may speculate that these three have a causal relation and even a genetic basis but further studies are needed to prove the same.

ECEL1 related distal arthrogryposis 5D in an Indian cohort-Report of recognizable musculoskeletal phenotype and a possible founder variant.

Distal arthrogryposis type 5D (DA5D) is clinically characterized by knee extension contractures, distal joint contractures, clubfoot, micrognathia, ptosis, and scoliosis. We report nine affected individuals from eight unrelated Indian families with DA5D. Although the overall musculoskeletal phenotype is not very distinct from other distal arthrogryposis, the presence of fixed knee extension contractures with or without scoliosis could be an important early pointer to DA5D. We also report a possible founder variant in ECEL1 along with four novel variants and further expand the genotypic spectrum of DA5D.

Bone mineral density in adults with arthrogryposis multiplex congenita: a retrospective cohort analysis.

The primary objective of this study was to evaluate the prevalence of low femoral and lumbar spine bone mineral density (BMD) in adults with arthrogryposis multiplex congenita (AMC). We performed a retrospective cohort analysis of adults with AMC who were enrolled in the French Reference Center for AMC and in the Pediatric and Adult Registry for Arthrogryposis (PARART, NCT05673265). Patients who had undergone dual-energy X-ray absorptiometry (DXA) and/or vitamin D testing were included in the analysis. Fifty-one patients (mean age, 32.9 ± 12.6 years) were included; 46 had undergone DXA. Thirty-two (32/51, 62.7%) patients had Amyoplasia, and 19 (19/51, 37.3%) had other types of AMC (18 distal arthrogryposis, 1 Larsen). Six patients (6/42, 14.3%) had a lumbar BMD Z score less than - 2. The mean lumbar spine Z score (- 0.03 ± 1.6) was not significantly lower than the expected BMD Z score in the general population. Nine (9/40, 22.5%) and 10 (10/40, 25.0%) patients had femoral neck and total hip BMD Z scores less than - 2, respectively. The mean femoral neck (- 1.1 ± 1.1) and total hip (- 1.2 ± 1.2) BMD Z scores in patients with AMC were significantly lower than expected in the general population (p < 0.001). Femoral neck BMD correlated with height (rs = 0.39, p = 0.01), age (rs = - 0.315, p = 0.48); total hip BMD correlated with height (rs = 0.331, p = 0.04) and calcium levels (rs = 0.41, p = 0.04). Twenty-five patients (25/51, 49.0%) reported 39 fractures. Thirty-one (31/36, 86.1%) patients had 25-hydroxyvitamin D levels less than 75 nmol/l, and 6 (6/36, 16.7%) had 25-hydroxyvitamin D levels less than 75 nmol/l. Adults with AMC had lower hip BMD than expected for their age, and they more frequently showed vitamin D insufficiency. Screening for low BMD by DXA and adding vitamin D supplementation when vitamin D status is insufficient should be considered in adults with AMC, especially if there is a history of falls or fractures.

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.

A Case Report: Can Prioritizing Sensory Integration Therapy Help Improve Gross Motor Function in a Rare Case of Neurogenic Arthrogryposis Multiplex Congenita?

Arthrogryposis multiplex congenital (AMC) is a congenital disorder diagnosed with extremity contractures, restricted joint range of motion, foot abnormalities, and hip dislocation. The current literature emphasizes medical and surgical management, but very few studies provide insight into physiotherapy management for AMC. We reported the case of a 16-month-old male diagnosed with AMC, operated on both hips for teratologic dislocation. Physiotherapy examination was conducted, and treatment was planned based on the principles of Sensory Integration Therapy (SIT) and neurodevelopmental technique (NDT) with orthosis to assist in functional recovery. He achieved motor milestones within one year of regular physiotherapy treatment. As per our literature search, this is the first study where an attempt has been made to utilize sensory integration along with NDT for the treatment of AMC, although the clinical presentation of the patient shows more musculoskeletal abnormalities.

[Myasthenia gravis-Gender aspects and family planning]. / Myasthenia gravis ­ Genderaspekte und Familienplanung.

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.

Arthrogryposis Multiplex Congenita and the Importance of Orthoses: A Case Report.

Arthrogryposis multiplex congenita (AMC) is a group of conditions characterized by multiple joint contractures. This rare disorder causes stiffness of joints, limiting the range of motion and negatively impacting activities of daily living (ADL). This case reports a 45-year-old male with AMC who was referred to physical medicine and rehabilitation (PMR). He had a limited range of movement in multiple joints and global muscle weakness. However, ADL were feasible, including walking. The patient had an unsteady barefoot gait, causing claudication, which improved significantly with adapted shoes. The primary goal of treatment is to improve the quality of life (QoL), and proper management should be promptly initiated. AMC requires a multidisciplinary approach to care with three mainstays of treatment: rehabilitation, orthoses, and corrective surgeries. Patients should be followed up periodically by their family doctors, and PMR evaluations and rehabilitation should be provided as needed. An orthopedic surgery consultation may be required for surgical interventions to provide optimal outcomes and augment the QoL.

Multiple Serial Casting for Recurrent Clubfoot in Arthrogryposis Corrects Deformity With Diminishing Returns.

PURPOSE: Arthrogryposis multiplex congenita (AMC) consists of more than 400 conditions involving severe joint contractures of at least two or more body regions. Management of clubfoot in patients with AMC is notoriously challenging, with a higher likelihood of recurrence than idiopathic clubfoot, which can be treated using the Ponseti technique to avoid or delay more invasive procedures. The purpose of this study is to determine the utility of multiple serial casting as a treatment of clubfoot in AMC using Pirani scores as an objective measure of deformity. METHODS: Pirani scores were retrospectively collected from 17 AMC patients with a total of 30 clubfeet and two years follow-up from initiation of treatment. Patients with a minimum of three casting series were included. Pre-treatment and post-treatment deformity scores were examined across casting series using analysis of variance (ANOVA) statistical analysis. RESULTS: The first series pre-treatment Pirani score improved from 4.80±1.54 to 1.68±1.48 (p<0.001). The second series improved from 4.23±1.03 to 2.72±0.916 (p<0.001). The third series had the smallest improvement from 3.87±1.07 to 2.82±1.02 (p<0.001). Change in Pirani scores showed a significant decrease from the first series to the second (p=0.001) and third (p<0.001). In addition, the number of casting days was found to significantly affect the change in scores during the third series (p=0.038). CONCLUSIONS: The Ponseti technique can improve clubfoot in AMC as measured by the Pirani score. Data shows that early intervention yields better results, with a diminished yet effective ability to elicit change over time.

Functional assessment of a novel biallelic MYH3 variation causing CPSKF1B (contractures, pterygia, and spondylocarpotarsal fusion syndrome1B).

BACKGROUND: The MYH3-associated myosinopathies comprise a spectrum of rare neuromuscular disorders mainly characterized by distal arthrogryposis with or without other features like pterygia and vertebrae fusion. CPSKF1B (contractures, pterygia, and spondylocarpotarsal fusion syndrome1B) is the only known autosomal recessiveMYH3-associated myosinopathy so far, with no more than two dozen cases being reported. MATERIALS AND METHODS: A boy with CPSKF1B was recruited and subjected to a comprehensive clinical and imaging evaluation. Genetic detection with whole-exome sequencing (WES) was performed on the patient and extended family members to identify the causative variation. A series of in silico and in vitro investigations were carried out to verify the pathogenicity of the two variants of the identified compound heterozygous variation. RESULTS: The patient exhibited moderate CPSKF1B symptoms including multiarticular contractures, webbed neck, and spondylocarpotarsal fusion. WES detected a compound heterozygous MYH3 variation consisting of two variants, namely NM_002470.4: c.3377A>G; p. (E1126G) and NM_002470.4: c.5161-2A>C. It was indicated that the NM_002470.4: c.3377A>G; p. (E1126G) variant mainly impaired the local hydrogen bond formation and impacted the TGF-B pathway, while the NM_002470.4: c.5161-2A>C variant could affect the normal splicing of pre-mRNA, resulting in the appearance of multiple abnormal transcripts. CONCLUSIONS: The findings of this study expanded the mutation spectrum of CPSKF1B, provided an important basis for the counseling of the affected family, and also laid a foundation for the functional study of MYH3 mutations.

Compound heterozygous variants in MYBPC1 lead to severe distal arthrogryposis type-1 manifestations.

Dominant missense variants in MYBPC1 encoding slow Myosin Binding Protein-C (sMyBP-C) have been increasingly linked to arthrogryposis syndromes and congenital myopathy with tremor. Herein, we describe novel compound heterozygous variants - NM_002465.4:[c.2486_2492del];[c.2663A > G] - present in fibronectin-III (Fn-III) C7 and immunoglobulin (Ig) C8 domains, respectively, manifesting as severe, early-onset distal arthrogryposis type-1, with the carrier requiring intensive care and several surgical interventions at an early age. Computational modeling predicts that the c.2486_2492del p.(Lys829IlefsTer7) variant destabilizes the structure of the Fn-III C7 domain, while the c.2663A > G p.(Asp888Gly) variant causes minimal structural alterations in the Ig C8 domain. Although the parents of the proband are heterozygous carriers for a single variant, they exhibit no musculoskeletal defects, suggesting a complex interplay between the two mutant alleles underlying this disorder. As emerging novel variants in MYBPC1 are shown to be causatively associated with musculoskeletal disease, it becomes clear that MYBPC1 should be included in relevant genetic screenings.

A mutation in F-actin polymerization factor suppresses the distal arthrogryposis type 5 PIEZO2 pathogenic variant in Caenorhabditis elegans.

The mechanosensitive PIEZO channel family has been linked to over 26 disorders and diseases. Although progress has been made in understanding these channels at the structural and functional levels, the underlying mechanisms of PIEZO-associated diseases remain elusive. In this study, we engineered four PIEZO-based disease models using CRISPR/Cas9 gene editing. We performed an unbiased chemical mutagen-based genetic suppressor screen to identify putative suppressors of a conserved gain-of-function variant pezo-1[R2405P] that in human PIEZO2 causes distal arthrogryposis type 5 (DA5; p. R2718P). Electrophysiological analyses indicate that pezo-1(R2405P) is a gain-of-function allele. Using genomic mapping and whole-genome sequencing approaches, we identified a candidate suppressor allele in the C. elegans gene gex-3. This gene is an ortholog of human NCKAP1 (NCK-associated protein 1), a subunit of the Wiskott-Aldrich syndrome protein (WASP)-verprolin homologous protein (WAVE/SCAR) complex, which regulates F-actin polymerization. Depletion of gex-3 by RNAi, or with the suppressor allele gex-3(av259[L353F]), significantly increased brood size and ovulation rate, as well as alleviating the crushed oocyte phenotype of the pezo-1(R2405P) mutant. Expression of GEX-3 in the soma is required to rescue the brood size defects in pezo-1(R2405P) animals. Actin organization and orientation were disrupted and distorted in the pezo-1 mutants. Mutation of gex-3(L353F) partially alleviated these defects. The identification of gex-3 as a suppressor of the pathogenic variant pezo-1(R2405P) suggests that the PIEZO coordinates with the cytoskeleton regulator to maintain the F-actin network and provides insight into the molecular mechanisms of DA5 and other PIEZO-associated diseases.

Effectiveness of the Ponseti method for congenital clubfoot in patients with arthrogryposis: A systematic review and meta-analysis of observational studies.

Purpose: The aim of this systematic review was to address the Ponseti method in arthrogrypotic clubfoot treatment and evaluate the success, complication, and recurrence rates. Method: A systematic review was performed in the PubMed, Scopus, Embase, and Web of Science databases on 9 January 2023, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Success, recurrence, and complication rates were evaluated and analyzed. Risks of bias and the quality of the studies were also evaluated. Results: Five case series, including 53 patients (102 feet), were identified. According to this model, the initial success rate was 91% (95% confidence interval = 0.79-0.96) with I2 = 43%, and the final success was 68% (at 5.8 years of follow-up). Recurrence rate was 30% (95% confidence interval = 0.14-0.52). Conclusion: Ponseti method is indicated in the initial treatment of arthrogrypotic clubfeet, as it is a minimally invasive method with a high correction rate (91%). However, a high recurrence rate (30%) requires early detection and adequate treatment. Level of evidence: Level III. PROSPERO Protocol: CRD42020210373.

Homologous mutations in human ß, embryonic, and perinatal muscle myosins have divergent effects on molecular power generation.

Mutations at a highly conserved homologous residue in three closely related muscle myosins cause three distinct diseases involving muscle defects: R671C in ß-cardiac myosin causes hypertrophic cardiomyopathy, R672C and R672H in embryonic skeletal myosin cause Freeman-Sheldon syndrome, and R674Q in perinatal skeletal myosin causes trismus-pseudocamptodactyly syndrome. It is not known whether their effects at the molecular level are similar to one another or correlate with disease phenotype and severity. To this end, we investigated the effects of the homologous mutations on key factors of molecular power production using recombinantly expressed human ß, embryonic, and perinatal myosin subfragment-1. We found large effects in the developmental myosins but minimal effects in ß myosin, and magnitude of changes correlated partially with clinical severity. The mutations in the developmental myosins dramatically decreased the step size and load-sensitive actin-detachment rate of single molecules measured by optical tweezers, in addition to decreasing overall enzymatic (ATPase) cycle rate. In contrast, the only measured effect of R671C in ß myosin was a larger step size. Our measurements of step size and bound times predicted velocities consistent with those measured in an in vitro motility assay. Finally, molecular dynamics simulations predicted that the arginine to cysteine mutation in embryonic, but not ß, myosin may reduce pre-powerstroke lever arm priming and ADP pocket opening, providing a possible structural mechanism consistent with the experimental observations. This paper presents direct comparisons of homologous mutations in several different myosin isoforms, whose divergent functional effects are a testament to myosin's highly allosteric nature.

Simple Talectomy is a Beneficial Surgical Procedure for Talipes Equinovarus and Other Severe Neuromuscular Foot Deformities.

Noninvasive techniques are gold standard to redress Severe Neuromuscular Foot Deformity (SNFD). However, simple talectomy may be considered to obtain a stable, plantigrade, pain-free foot. We present a 10-year follow-up accessing radiological correction rates, functional outcomes, complications, and patient satisfaction. This retrospective case series evaluated talectomies in 2012 to 2022. Simple talectomy was combined with Steinman pin fixation of calcaneus to tibia for approximately 6 weeks. Diagnoses primarily included arthrogryposis multiplex congenita and cerebral palsy. Indications were pain, wounds/pressure marks, severe rigidity, and residual/recurrent deformity. The primary outcome was radiological correction. Tibiotalar angle (TiTa) and tibiocalcaneal angle (TiCa) were measured on mediolateral projections. Secondary outcomes were functional scores of pain/deformity graded as good, fair or poor. Furthermore, validated patient-reported outcome measures, that is, EQ-5D-5L and the Scoliosis Research Society-30 Questionnaire (2 items) assessed health-related quality of life and patient satisfaction. Nineteen talectomies in 11 patients were analyzed. Mean follow-up was 62 months (range 9-112 months). Mean TiTa was 137° (95%CI 128;146). TiCa improved significantly: Mean difference -24° (95%CI -44;-5, p = .02). All feet became plantigrade and pain-free with no skin issues. Functional outcomes were graded as 9/19 good, 10/19 fair and 0/19 poor. Parents/primary caregivers were mainly satisfied. Perceived health was 54 (95%CI 34;75) out of 100 on a visual analogue scale, emphasizing complex medical conditions. In conclusion, simple talectomy is a suitable salvage procedure for SNFD.

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.

Arthrogryposis multiplex congenita: dental and maxillofacial phenotype - A scoping review.

INTRODUCTION: Arthrogryposis multiplex congenita (AMC) is a heterogeneous group of disorders associated with decreased fetal movement, with a prevalence between 1/3000 and 1/5200 live births. Typical features of AMC include multiple joint contractures present at birth, and can affect all joints of the body, from the jaw, and involving the upper limbs, lower limbs and spine. The jaws may be affected in 25 % of individuals with AMC, with limited jaw movement and mouth opening. Other oral and maxillofacial deformities may be present in AMC, including cleft palate, micrognathia, periodontitis and delayed teething. To our knowledge, oral and maxillofacial abnormalities have not been systematically assessed in individuals with AMC. Therefore, this scoping review was conducted to identify, collect, and describe a comprehensive map of the existing knowledge on dental and maxillofacial involvement in individuals with AMC. METHODOLOGY: A scoping review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines. The PRISMA guidelines for scoping reviews were followed and databases were searched for empirical articles in English and French published until October 2022. We searched MEDLINE, Embase, Web of Science and ERIC databases. Two authors independently reviewed the articles and extracted the data. RESULTS: Of a total of 997 studies that were identified, 96 met the inclusion criteria and were subsequently included in this scoping review. These 96 studies collectively provided insights into 167 patients who exhibited some form of oral and/or maxillofacial involvement. Notably, 25 % of these patients were within the age range of 0-6 months. It is worth highlighting that only 22 out of the 96 studies (22.9 %), had the primary objective of evaluating dental and/or maxillofacial deformities. Among the patients studied, a prevalent pattern emerged, revealing that severe anomalies such as micrognathia (56 %), high-arched palate (29 %), cleft palate (40 %), limited mouth opening (31 %), and dental anomalies (28 %) were frequently observed. Importantly, many of these patients were found to have more than one of these anomalies. Even though these maxillofacial impairments are known to be associated with dental problems (e.g., cleft palate is associated with oligodontia, hypodontia, and malocclusion), their secondary effects on the dental phenotype were not reported in the studies. CONCLUSION: Our findings have uncovered a notable deficiency in existing literature concerning dental and maxillofacial manifestations in AMC. This underscores the need for interdisciplinary collaboration and the undertaking of extensive prospective cohort studies focused on AMC. These studies should assess the oral and maxillofacial abnormalities that can impact daily functioning and overall quality of life.

Phenotypic heterogeneity associated with KIF21A: Two new cases and review of the literature.

Our understanding of genetic and phenotypic heterogeneity associated with the clinical spectrum of rare diseases continues to expand. Thorough phenotypic descriptions and model organism functional studies are valuable tools in dissecting the biology of the disease process. Kinesin genes are well known to be associated with specific disease phenotypes and a subset of kinesin genes, including KIF21A, have been associated with more than one disease. Here we report two patients with KIF21A variants identified by exome sequencing; one with biallelic variants, supporting a novel KIF21A related syndrome with recessive inheritance and the second report of this condition, and another with a heterozygous de novo variant allele representing a phenotypic expansion of the condition described to date. We provide detailed phenotypic information on both families, including a novel neuropathology finding of neuroaxonal dystrophy associated with biallelic variants in KIF21A. Additionally, we studied the dominant variant in Saccharomyces cerevisiae to assess variant pathogenicity and found that this variant appears to impair protein function. KIF21A associated disease has mounting evidence for phenotypic heterogeneity; further patients and study of an allelic series are required to define the phenotypic spectrum and further explore the molecular etiology for each of these conditions.

Effects of Powerchair Football: Contextual Factors That Impact Participation.

The aim of this study was to identify contextual factors that negatively affect activity and participation among powerchair football (PF) players. Thirty-seven semistructured interviews were conducted with PF players (Mage = 27.9 ± 8.2 years) in France (n = 18) and the United States (n = 19). Participants reported acute back and neck pain as the primary morbidities resulting from PF participation, with sustained atypical posture in the sport chair as the primary cause. Competition-related physical and mental stress were also identified as participation outcomes. Accompanying the many benefits of PF, participants recognized negative impacts of discomfort, physical fatigue, and mental fatigue. Interventions such as seating modifications, thermotherapy to combat pain, napping to combat acute physical stress, and mental preparation to manage state anxiety were all identified as prospective interventions.

Diagnóstico prenatal, síndrome Freeman-Sheldon mediante ultrasonido y estudio genético. Reporte de caso / Prenatal diagnosis of Freeman-Sheldon syndrome using ultrasound and genetic testing. Case report

Objetivos: Describir un caso de diagnóstico prenatal de síndrome de Freeman-Sheldon mediante hallazgos ecográficos y secuenciación completa del exoma fetal. Materiales y métodos: Mujer de 33 años, con antecedentes de hipotiroidismo en tratamiento, a quien en semana 19 se realizó ecografía de detalle anatómico, en la cual se observaron deformidades en el feto en más de dos áreas corporales (extremidades superiores e inferiores), sugiriendo el diagnóstico de artrogriposis. Posteriormente, se brindó asesoría genética y se realizó amniocentesis en semana 20 de gestación, con análisis de la hibridación in situ por fluorescencia, seguido de secuenciación completa del exoma fetal. Este último examen permitió identificar una variante patogénica heterocigota en el gen MYH3, la cual se asocia con la artrogriposis distal tipo 2A. Conclusiones: La realización de la secuenciación completa de exoma fetal es un factor clave para identificar la mutación del gen MYH3, y confirma que las deformidades evidenciadas por ultrasonido estaban relacionadas con la artrogriposis distal tipo 2A. Es importante hacer la secuenciación de exoma fetal en fetos que muestren hallazgos de malformaciones articulares en el ultrasonido prenatal.

Objectives: To describe a case of prenatal diagnosis of Freeman-Sheldon syndrome based on ultrasound findings and complete fetal exome sequencing. Materials and methods: A 33-year-old woman currently on treatment for hypothyroidism in whom a 19-week detailed anatomical ultrasound scan showed fetal deformities in more than two body areas (upper and lower limbs), suggesting a diagnosis of arthrogryposis. Genetic counseling was provided and amniocentesis was performed at 20 weeks for fluorescence in situ hybridization (FISH) analysis and complete fetal exome sequencing, with the latter allowing the identification of a heterozygous pathogenic variant of the MYH3 gene which is associated with type 2A distal arthrogryposis. Conclusions: Complete fetal exome sequencing was a key factor in identifying the MYH3 gene mutation and confirmed that the deformities seen on ultrasound were associated with type 2A distal arthrogryposis. It is important to perform complete fetal exome sequencing in cases of joint malformations seen on prenatal ultrasound.

Muscular phenotype description of abnormal THOC2 splicing.

Until recently, the disease known to be associated with THOC2 mutations was Intellectual developmental disorder, X-linked 12 (MIM300957). However, recently, fetal arthrogryposis multiplex congenita has been associated with a specific splice site mutation in the THOC2 gene. We report a family with the same splice site mutation in the THOC2 gene involved in fetal arthrogryposis as well. We provide the first description of the muscular phenotype of this disease which reveals the presence of cytoplasmic bodies. Our findings expand the clinical phenotype of THOC2 gene related defects.