OBJECTIVE: Hereditary neuropathy with liability to pressure palsy (HNPP) is a rare autosomal dominant peripheral neuropathy, usually caused by heterozygous deletion mutations in the peripheral myelin protein 22 (PMP22) gene. This study aims to investigate the clinical and molecular genetic characteristics of HNPP.
METHODS: HNPP patients in the Department of Neurology at Third Xiangya Hospital of Central South University from 2009 to 2023 were included in this study. The general clinical data, nervous electrophysiological and molecular genetic examination results were collected and analyzed. Molecular genetic examination was to screen for deletion of PMP22 gene using multiplex ligation-dependent probe amplification (MLPA) after extracting genomic DNA from peripheral blood; and if no PMP22 deletion mutation was detected, next-generation sequencing was used to screen for PMP22 point mutations. The related literatures of HNPP were reviewed, and the clinical and molecular genetic characteristics of HNPP patients were analyzed.
RESULTS: A total of 34 HNPP patients from 24 unrelated Chinese Han families were included in this study, including 25 males and 9 females. The average age at illness onset was 22.0 years. Sixty-two point five percent of the families had a positive family history. Among them, 30 patients had symptoms of peripheral nerve paralysis. Patients often presented with paroxysmal single limb weakness with (or) numbness (25/30), and some patients had paroxysmal unilateral recurrent laryngeal nerve (vagus nerve) paralysis (2/30). Physical examination revealed muscle weakness (23/29), hypoesthesia (9/29), weakened or absent ankle reflexes (20/29), distal limb muscle atrophy (8/29) and high arched feet (5/29). Most patients (26/30) could fully recover to normal after an acute attack. Thirty-one patients in our group underwent nervous electrophysiological examination, and showed multiple demyelinating peripheral neuropathies with both motor and sensory nerves involved. Most patients showed significantly prolonged distal motor latency (DML), mild to moderate nerve conduction velocity slowing, decreased amplitude of compound muscle action potential (CMAP) and sensory nerve action potential (SNAP), and sometimes with conduction block. Nerve motor conduction velocity was (48.5±5.5) m/s, and the CMAP amplitude was (8.4±5.1) mV. Nerve sensory conduction velocity was (37.4±10.5) m/s, and the SNAP amplitude was (14.4±15.2) μV. There were 24 families, 23 of whom had the classical PMP22 deletion, the last one had a heterozygous pathogenic variant in the PMP22 gene sequence (c.434delT). By reviewing clinical data and genetic testing results of reported 1 734 HNPP families, we found that heterozygous deletion mutation of PMP22 was the most common pathogenic mutation of HNPP (93.4%). Other patients were caused by PMP22 small mutations (4.0%), PMP22 heterozygous gross deletions (0.6%), and PMP22 complex rearrangements (0.1%). Thirty-eight sorts of HNPP-related PMP22 small mutations was reported, including missense mutations (10/38), nonsense mutations (4/38), base deletion mutations (13/38), base insertion mutations (3/38), and shear site mutations (8/38). HNPP patients most often presented with episodic painless single nerve palsy. Common peroneal nerve, ulnar nerve, and brachial plexus nerve were the most common involved nerves, accounting for about 75%. Only eighteen patients with cranial nerve involved was reported.
CONCLUSIONS: Heterozygous deletion mutation of PMP22 is the most common pathogenic mutation of HNPP. Patients is characterized by episodic and painless peripheral nerve paralysis, mainly involving common peroneal nerve, ulnar nerve, and other peripheral nerves. Nervous electrophysiological examination has high sensitivity and specificity for the diagnosis of HNPP, which is manifested by extensive demyelinating changes. For patients with suspected HNPP, nervous electrophysiological examination and PMP22-MLPA detection are preferred. Sanger sequencing or next generation sequencing can be considered to detect other mutations of PMP22.
目的: 遗传性压力易感性周围神经病(hereditary neuropathy with liability to pressure palsy，HNPP)是一种少见的常染色体显性遗传周围神经病，通常由周围髓鞘蛋白22(peripheral myelin protein 22，PMP22)基因杂合缺失突变引起。本研究旨在探讨HNPP患者的临床和分子遗传学特征。方法: 纳入2009至2023年就诊于中南大学湘雅三医院神经内科的HNPP患者，收集并分析患者的一般临床资料、神经电生理和分子遗传学检查结果。分子遗传学检查为提取外周血基因组DNA后采用多重连接探针扩增技术(multiplex ligation-dependent probe amplification，MLPA)进行PMP22大片段缺失的筛查；若未检测到PMP22缺失突变，则用二代测序法筛查PMP22点突变。进一步对HNPP相关文献进行回顾，分析HNPP患者的临床和分子遗传学特征。结果: 共纳入来自24个无血缘关系的中国汉族家系的34例HNPP患者，包括25名男性和9名女性，平均22.0岁起病，有阳性家族史的家系占62.5%。30例患者出现周围神经麻痹的症状，常表现为发作性单肢无力伴/或麻木(25/30)，亦可表现为发作性单侧喉返神经(迷走神经)麻痹(2/30)。体格检查可发现受累神经相应支配区域的肌肉无力(23/29)和浅感觉减退(9/29)，踝反射减弱或消失(20/29)，肢体远端肌肉萎缩(8/29)及高弓足(5/29)。多数患者(26/30)在急性发作后可完全恢复正常。有31例患者完成神经电生理检查，均表现为多发性周围神经损害，以运动及感觉神经髓鞘损害为主，多数患者可有远端运动潜伏期(distal motor latency，DML)明显延长，轻至中度的神经传导速度减慢，复合肌肉动作电位(compound muscle action potential，CMAP)及感觉神经动作电位(sensory nerve action potential，SNAP)波幅降低，有时可出现传导阻滞。正中神经运动传导速度为(48.5±5.5) m/s，CMAP波幅为(8.4±5.1) mV；正中神经感觉传导速度为(37.4±10.5) m/s，SNAP波幅为(14.4±13.0) μV。在24个HNPP家系中，经MLPA检测证实有23个家系为PMP22杂合缺失突变导致，经二代测序证实剩余1个家系为PMP22 c.434delT突变所致。文献检索到1 734个进行了基因检测的HNPP确诊家系，其基因检测结果再次证实了PMP22杂合缺失突变是最常见的突变类型，占93.4%，其余突变类型包括PMP22微小突变(4.0%)、PMP22杂合不完全缺失突变(0.6%)、PMP22复杂易位突变(0.1%)。目前HNPP相关的PMP22微小突变共报道38种，包括错义突变(10/38)、无义突变(4/38)、碱基缺失突变(13/38)、碱基插入突变(3/38)、剪切位点突变(8/38)。HNPP患者最常表现为发作性无痛性单神经麻痹，腓总神经、尺神经和臂丛神经受累最为常见，约占75%。颅神经受累的患者仅有18例报道。结论: PMP22杂合缺失突变是HNPP最常见的突变类型。HNPP以发作性无痛性单神经麻痹为主要特点，主要累及腓总神经、尺神经等周围神经。神经电生理检查对于诊断本病具有较高的灵敏度和特异度，表现为广泛的脱髓鞘改变。对于怀疑HNPP的患者，首选完善神经电生理检查及PMP22大片段杂合缺失的检测。必要时可以完善Sanger测序或二代测序，对PMP22其他突变类型进行检测以防漏诊。.

UNASSIGNED: The aim of this systematic review was to address the Ponseti method in arthrogrypotic clubfoot treatment and evaluate the success, complication, and recurrence rates.
UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: 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.
UNASSIGNED: Level III.
UNASSIGNED: CRD42020210373.

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.
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.
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.
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.

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.

Congenital arthrogryposis (CA) refers to the presence of multiple contractures at birth. It is a feature of several inherited syndromes, notable amongst them are disorders of collagen formation. This review aims to characterize disorders that directly or indirectly impact collagen structure and function leading to CA in search for common phenotypic or pathophysiological features, possible genotype-phenotype correlation, and potential novel treatment approaches based on a better understanding of the underlying pathomechanism. Nine genes, corresponding to five clinical phenotypes, were identified after a literature search. The most notable trend was the extreme phenotype variability. Clinical features across all syndromes ranged from subtle with minimal congenital contractures, to severe with multiple congenital contractures and extra-articular features including skin, respiratory, or other manifestations. Five of the identified genes were involved in the function of the Lysyl Hydroxylase 2 or 3 enzymes, which enable the hydroxylation and/or glycosylation of lysyl residues to allow the formation of the collagen superstructure. Whilst current treatment approaches are post-natal surgical correction, there are also potential in-utero therapies being developed. Cyclosporin A showed promise in treating collagen VI disorders although there is an associated risk of immunosuppression. The treatments that could be in the clinical trials soon are the splice correction therapies in collagen VI-related disorders.

LRP5 high bone mass (HBM) is an autosomal dominant endosteal hyperostosis caused by mutations of the low-density lipoprotein receptor-related protein 5 (LRP5) gene. Alternative names included \"autosomal dominant osteosclerosis\" and \"Worth disease.\" The aim of the paper is to provide an historical overview of a disorder whose literature is complicated and confusing due to the past use of several denominations and lack of reviews.
We collected case reports of HBM with evidence of autosomal dominant transmission preceding the identification of the LRP5 mutations in 2002 (Worth-type endosteal hyperostosis) and cases of LRP5 HBM confirmed by genetic analysis since 2002. The prevalence of relevant clinical and laboratory findings was estimated. We described an affected woman with neurological manifestations.
A 44-year-old Caucasian woman with torus palatinus complained of headache, hypo-/anosmia, and complete mixed deafness. Dual-energy X-ray absorptiometry (DEXA) scan revealed elevated bone mass. The A242T mutation of the LRP5 gene was detected. Including the present case, 155 patients have been reported to date. Neurological involvement and increased serum alkaline phosphatase (ALP) were present in 19.4% and 3.7% of cases, respectively. Facial changes and torus palatinus were observed in 61% and 41% of cases, respectively.
We present the only historical review on Worth-type endosteal hyperostosis, now known as LRP5 HBM. Neurological manifestations, previously considered absent in the disease, affect 19.4% of the patients. Genetic analysis and appropriate denomination of LRP5 HBM are fundamental for diagnosis and to mitigate the confusion that has long characterized this disease.

Townes-Brocks syndrome is a rare autosomal dominant genetic syndrome caused by mutations in SALL1. The clinical features of Townes-Brocks syndrome are highly heterogonous. Identification of new SALL1 mutations and study of the relation between SALL1 mutations and clinical features can facilitate diagnosis of Townes-Brocks syndrome.
We collected clinical data and blood samples of the two patients and their family members for whole-exome sequencing and Sanger sequencing. Prediction analysis of the SALL1variation protein structure was achieved using Alphafold. The clinical materials and gene sequencing results were analyzed. The clinical materials and gene sequencing results were analyzed. The related literature of Townes-Brocks syndrome were searched and the genotype-renal phenotype analysis was performed combined with this two cases.
Based on the clinical features and gene sequencing results, the two patients were diagnosed as Townes-Brocks syndrome. Two novel SALL1 mutations (c.878-887del and c.1240G > T) were identified, both of which were pathogenic mutations. The correlation between genotypes and renal phenotypes in Townes-Brocks syndrome patients caused by SALL1 mutation were summarized.
This study identified two novel mutations and provided new insights into the correlation of genotypes and renal phenotypes of Townes-Brocks syndrome.

Arthrogryposis multiplex congenita (AMC) is defined as \"a group of congenital conditions characterized by joint contractures in two or more body areas.\" Given its heterogeneity, the definition of AMC has changed multiple times. This scoping review provides an overview of how AMC is defined in scientific publications, on existing knowledge and trends regarding the concept of AMC. Our review illuminates possible knowledge gaps and provides directions for future research. A scoping review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines. Quantitative studies on AMC from 1995 to date were included. We summarized information about definitions/descriptions of AMC, study objectives, study designs, methods, funding, and involvement of patient organizations. A total of 2729 references were screened, and 141 articles fulfilled our inclusion criteria. Our scoping revealed that the majority of publications were cross-sectional or retrospective studies of children and young people, commonly about orthopedic management. Explicit or good definitions of AMC were provided in 86% of the cases. Recent publications on AMC mostly used consensus-based definitions. The research gaps were primarily related to adults, aging, etiology, and new medical treatment, in addition to implications on daily life.

Objective: Pathogenic variants in NEK9 (MIM: 609798) have been identified in patients with lethal congenital contracture syndrome 10 (OMIM: 617022) and arthrogryposis, Perthes disease, and upward gaze palsy (APUG and OMIM: 614262). The shared core phenotype is multiple joint contractures or arthrogryposis. In the present study, three novel variants of NEK9 associated with neonatal arthrogryposis were reported. Methods: The clinical data of two premature infants and their parents were collected. The genomic DNA was extracted from their peripheral blood samples and subjected to trio-whole-exome sequencing (trio-WES) and copy number variation analysis. Results: Using trio-WES, a total of three novel pathogenic variants of NEK9 were detected in the two families. Patient 1 carried compound heterozygous variations of c.717C > A (p. C239*741) and c.2824delA (p.M942Cfs*21), which were inherited from his father and mother, respectively. Patient 2 also carried compound heterozygous variations of c.61G > T (p. E21*959) and c. 2824delA (p. M942Cfs*21), which were inherited from his father and mother, respectively. These variants have not been previously reported in the ClinVar, HGMD, or gnomAD databases. Conclusion: This is the first report about NEK9-related arthrogryposis in neonatal patients. The findings from this study suggest that different types of mutations in NEK9 lead to different phenotypes. Our study expanded the clinical phenotype spectrum and gene spectrum of NEK9-associated arthrogryposis.

OBJECTIVE: Amyoplasia congenita is the most frequent type of arthrogryposis causing fetal hypokinesia, leading to congenital contractures at birth. The pathogenesis is thought to be impaired blood circulation to the fetus early in pregnancy, with hypotension and hypoxia damaging the anterior horn cells. In animal studies however a prenatal infection with a poliomyelitis-like viral agent was demonstrated. Congenital Zika virus syndrome (CZVS) has recently been described in infants with severe microcephaly, and in 10-25% of cases arthrogryposis.
METHODS: A search in PubMed for CZVS yielded 124 studies. After a selection for arthrogryposis, 35 papers were included, describing 144 cases. The studies were divided into two categories. 1) Those (87 cases) focussing on imaging or histological data of congenital brain defects, contained insufficient information to link arthrogryposis specifically to lesions of the brain or spinal motor neuron. 2) In the other 57 cases detailed clinical data could be linked to neurophysiological, imaging or histological data.
RESULTS: In category 1 the most frequent brain abnormalities in imaging studies were ventriculomegaly, calcifications (subcortical, basal ganglia, cerebellum), hypoplasia of the brainstem and cerebellum, atrophy of the cerebral cortex, migration disorders and corpus callosum anomalies. In category 2, in 38 of 57 cases clinical data were indicative of Amyoplasia congenita. This diagnosis was confirmed by electromyographic findings (13 cases), by MRI (37 cases) or histology (12 cases) of the spinal cord. The latter showed small or absent lateral corticospinal tracts, and cell loss and degeneration of motor neuron cells. Zika virus-proteins and flavivirus-like particles were detected in cytoplasm of spinal neurons.
CONCLUSIONS: The phenotype of arthrogryposis in CZVS is consistent with Amyoplasia congenita. These findings warrant search for an intrauterine infection with any neurotropic viral agent with affinity to spinal motor neurons in neonates with Amyoplasia.