PIGW-related glycosylphosphatidylinositol deficiency: A case report and literature review.

INTRODUCTION: PIGW-related glycosylphosphatidylinositol deficiency is a rare disease that manifests heterogeneous clinical phenotypes. METHODS: We describe a patient with PIGW deficiency and summarize the clinical characteristics of the case. In addition, we conducted a literature review of previously reported patients with pathogenic variants of PIGW. RESULTS: A Chinese girl presented with refractory epilepsy, severe intellectual disability, recurrent respiratory infections, and hyperphosphatasia. Seizures worsened during fever and infections, making her more susceptible to epileptic status. She was found to carry a heterozygous variant of PIGW and a deletion of chromosome 17q12 containing PIGW. Only six patients with homozygous or compound heterozygous pathogenic variants of PIGW have been identified in the literature thus far. Epileptic seizures were reported in all patients, and the most common types of seizures were epileptic spasms. Distinctive facial and physical features and recurrent respiratory infections are common in these patients with developmental delays. Serum alkaline phosphatase (ALP) levels were elevated in four of the six patients. CONCLUSIONS: PIGW-related glycosylphosphatidylinositol deficiency is characterized by developmental delay, epilepsy, distinctive facial features, and multiple organ anomalies. Genetic testing is an important method for diagnosing this disease, and flow cytometry and serum ALP level detection are crucial complements for genetic testing.

Spinal muscular atrophy with hypoplasia of the corpus callosum: a case report.

BACKGROUND: Spinal Muscular Atrophy (SMA) is a severe neuromuscular disorder due to a defect in the survival motor neuron 1 (SMN1) gene. Hypoplasia of the corpus callosum is underdevelopment or thinness of the corpus callosum. SMA and callosal hypoplasia are relatively rare, and there is limited information sharing the diagnosis and treatment for SMA patients with callosal hypoplasia. CASE DESCRIPTION: A boy with callosal hypoplasia, small penis, and small testes had been perceived with motor regression at 5 months. He was referred to the rehabilitation department and neurology department at 7 months. Physical examination showed absent deep tendon reflexes, proximal weakness and significant hypotonia. He was recommended to perform trio whole-exome sequencing (WES) and array comparative genomic hybridization (aCGH) for his complicated conditions. The subsequent nerve conduction study revealed some characteristics of motor neuron diseases. We identified a homozygous deletion in exon 7 of the SMN1 gene by multiplex ligation-dependent probe amplification and failed to find further pathogenic variations responsible for multiple malformations by trio WES and aCGH. He was diagnosed as SMA. Despite some concerns, he received the therapy of nusinersen for nearly 2 years. He gained the milestone of sitting without support, which he had never accomplished, after the seventh injection, and he continued to improve. During follow-up, there were no adverse events reported and no signs of hydrocephalus. CONCLUSIONS: Some extra features which could not belong to neuromuscular manifestation made the diagnosis and treatment of SMA more complicated.

Maternal secretin ameliorates obesity by promoting white adipose tissue browning in offspring.

Our knowledge of the coordination of intergenerational inheritance and offspring metabolic reprogramming by gastrointestinal endocrine factors is largely unknown. Here, we showed that secretin (SCT), a brain-gut peptide, is downregulated by overnutrition in pregnant mice and women. More importantly, genetic loss of SCT in the maternal gut results in undesirable phenotypes developed in offspring including enhanced high-fat diet (HFD)-induced obesity and attenuated browning of inguinal white adipose tissue (iWAT). Mechanistically, loss of maternal SCT represses iWAT browning in offspring by a global change in genome methylation pattern through upregulation of DNMT1. SCT functions to facilitate ubiquitination and degradation of DNMT1 by activating AMPKα, which contributes to the observed alteration of DNMT1 in progeny. Lastly, we showed that SCT treatment during pregnancy can reduce the development of obesity and improve glucose tolerance and insulin resistance in offspring of HFD-fed females, suggesting that SCT may serve as a novel biomarker or a strategy for preventing metabolic diseases.

Comprehensive profile and natural history of pediatric patients with spinal muscular atrophy: A large retrospective study from China.

Background: There is a large population of people with spinal muscular atrophy (SMA) in China, and new disease-modifying therapies have become available recently. However, comprehensive data on the management and profile of treatment-naive SMA patients in China are still lacking. Methods: As a retrospective study, a large cohort of treatment-naive patients with clinical and genetic diagnoses of 5q SMA were enrolled, ranging from neonatal to 18 years old, from the Neurology Department of Children's Hospital of Fudan University between January 2013 and December 2020. The data regarding their clinical presentations, genetic defects, motor function assessment results, and follow ups were reviewed. Results: We enrolled 392 SMA patients (male: female = 189: 203): 1a = 46, 1b = 44, 1c = 31, 2a = 119, 2b = 56, 3a = 52, 3b = 14, from 27 of the 34 administrative districts in China, and 389 patients harbored homozygous deletion of exon 7 in the SMN1 gene (99.2%). The median age of onset was 0.08 (range: 0-0.30), 0.25 (0.06-0.60), 0.42 (0.08-1.50), 0.67 (0.07-5.08), 1.0 (0.40-1.83), 1.5 (1.00-3.00), and 4.04 (1.80-12.00) years old for SMA 1a, 1b, 1c, 2a, 2b, 3a, and 3b patients, while the median age of first assessment was 0.25 (0.08-2.60), 0.42 (0.17-1.90), 0.80 (0.17-4.5), 2.50 (0.5-15.83), 2.92 (1.08-13.42), 4.25 (1.58-17.33), and 7.34 (3.67-14.00) years old, respectively. Patients were followed up with for up to 15.8 years. The median event-free survival time was 7 months, 15 months, and indeterminate in SMA 1a, 1b, and 1c patients (p < 0.0001), with a better survival situation for higher SMN2 copies (p = 0.0171). The median age of sitting loss was 5.75 years and 13.5 years in SMA 2a and 2b (p = 0.0214) and that of ambulation loss was 9.0 years and undefined in SMA 3a and 3b (p = 0.0072). Cox regression analysis showed that higher SMN2 copies indicated better remaining ambulation in SMA 3. The median time to develop orthopedic deformities was 4.5, 5.2, and 10.1 years in SMAs 1c, 2, and 3, respectively (p < 0.0001), with a possible trend of better preservation of joint function for patients under regular rehabilitation (p = 0.8668). Conclusion: Our study elucidated insight into the comprehensive management and profile of different types of SMA patients in China, providing a clinical basis for assessing the efficacy of new therapies.

Phenotypes and genotypes of mitochondrial diseases with mtDNA variations in Chinese children: A multi-center study.

Mitochondrial DNA (mtDNA) associated mitochondrial diseases hold a crucial position but comprehensive and systematic studies are relatively rare. Among the 262 patients of four children's hospitals in China, 96%-point mutations (30 alleles in 11 genes encoding tRNA, rRNA, Complex I and V) and 4%-deletions (seven of ten had not been reported before) were identified as the cause of 14 phenotypes. MILS presented the highest genetic heterogeneity, while the m.3243A > G mutation was the only "hotspot" mutation with a wide range of phenotypes. The degrees of heteroplasmy in the leukocytes of MM were higher than MELAS. The heteroplasmy level of patients was higher than that in mild and carrier group, while we found low-level heteroplasmy pathogenic mutations as well. Some homoplasmic variations (e.g., m.9176 T > C mutation) are having high incomplete penetrance. For a suspected MELAS, m.3243A > G mutation was recommended to detect first; while for a suspected LS, trios-WES and mtDNA genome sequencing by NGS were recommended first in both blood and urine.

Myotonia Congenita: Clinical Characteristic and Mutation Spectrum of CLCN1 in Chinese Patients.

Background: CLCN1-related myotonia congenita (MC) is one of the most common forms of non-dystrophic myotonia, in which muscle relaxation is delayed after voluntary or evoked contraction. However, there is limited data of clinical and molecular spectrum of MC patients in China. Patients and Methods: Five patients with myotonia congenita due to mutations in CLCN1 gene were enrolled, which were identified through trio-whole-exome sequencing or panel-based next-generation sequencing test. The clinical presentation, laboratory data, electrophysiological tests, muscular pathology feature, and genetic results were collected and reviewed. We also searched all previously reported cases of MC patients with genetic diagnosis in Chinese populations, and their data were reviewed. Results: The median onset age of five patients was 3.0 years old, ranging from 1.0 to 5.0 years old, while the median age of admit was 5.0 years old, ranging from 3.5 to 8.8 years old. Five patients complained of muscle stiffness when rising from chairs or starting to climb stairs (5/5, 100.0%), four patients complained of delayed relaxation of their hands after forceful grip (4/5, 80.0%), all of which improved with exercise (warm-up phenomenon) (5/5, 100%). Electromyogram was conducted in five patients, which all revealed myotonic change (100%). Genetic tests revealed nine potential disease-causing variants in CLCN1 gene, including two novel variants: c.962T>A (p.V321E) and c.1250A>T (p.E417V). Literature review showed that 43 MC Chinese patients with genetic diagnosis have been reported till now (including our five patients). Forty-seven variants in CLCN1 gene were found, which consisted of 33 missense variants, 6 nonsense variants, 5 frame-shift variants, and 3 splicing variants. Variants in exon 8, 15, 12, and 16 were most prevalent, while the most common variants were c.892G>A (p.A298T) (n = 9), c.139C>T (p.R47W) (n = 3), c.1205C>T(p.A402V) (n = 3), c.1657A>T (p.I553F) (n = 3), c.1679T>C (p.M560T) (n = 3), c.350A>G (p.D117G) (n = 2), c.762C>G (p.C254W) (n = 2), c.782A>G (P.Y261C) (n = 2), and c.1277C>A (p.T426N) (n = 2). Conclusion: Our results reported five CLCN1-related MC patients, which expanded the clinical and genetic spectrum of MC patients in China. Based on literature review, 43MC Chinese patients with genetic diagnosis have been reported till now, and variants in exon eight were most prevalent in Chinese MC patients while c.892G>A (p.A298T) was probably a founder mutation.

Clinical and Genetic Characteristics of Mitochondrial Encephalopathy Due to FOXRED1 Mutations: Two Chinese Case Reports and a Review of the Literature.

Background: As one of the assembly factors of complex I in the mitochondrial respiratory chain, FOXRED1 plays an important role in mitochondrial function. However, only a few patients with mitochondrial encephalopathy due to FOXRED1 defects have been reported. Methods: Two Chinese patients with mitochondrial encephalopathy due to mutations in FOXRED1 were identified through trio whole-exome sequencing. The clinical presentation, laboratory data, brain imaging findings, and genetic results were collected and reviewed. All previously reported cases with FOXRED1-related mitochondrial encephalopathy were collected using a PubMed search, and their data were reviewed. Results: Two patients presented with severe neurodevelopmental delay, epilepsy, high lactic acid levels, and remarkable diffuse brain atrophy and polycystic encephalomalacia during early infancy. Trio whole-exome sequencing revealed compound heterozygous variants in both patients: one case harbored a c.606_607delAG frameshift variant and a c.1054C>T (p.R352W) variant. At the same time, the other carried a novel c.352C>T (p.Q118X) variant and a reported c.1054C>T (p.R352W) variant. To date, nine patients have been reported with FOXRED1 defects, including our two cases. The most common presentations were neurodevelopment delay (100%), epilepsy (80%), poor feeding (30%), and vision loss (20%). Multisystem involvement comprised cardiovascular dysfunction (30%), abnormal liver function (20%), and hypoglycemia (10%). The neuroimaging results ranged from normal to severe cerebral atrophy and polycystic encephalomalacia in early infancy. Eleven pathogenic variants in FOXRED1 have been reported, comprising six missense variants, two non-sense variants, two frameshift variants, and one splice variant; among these the c.1054C>T (p.R352W) and c.612_615dupAGTG (p.A206SfsX15) variants are more common. Conclusion: FOXRED1-related mitochondrial disorders have high clinical and genetic heterogeneity. Our study expanded the clinical and genetic spectrum of FOXRED1 defects. Early infantile onset and progressive encephalopathy are the most common clinical presentations, while the variants c.1054C>T (p.R352W) and c.612_615dupAGTG (p.A206SfsX15) may be critical founder mutations.

Clinical Profile and Outcome of Pediatric Mitochondrial Myopathy in China.

Introduction: Mitochondrial myopathy in children has notable clinical and genetic heterogeneity, but detailed data is lacking. Patients and Methods: In this study, we retrospectively reviewed the clinical presentation, laboratory investigation, genetic and histopathological characteristics, and follow-ups of 21 pediatric mitochondrial myopathy cases from China. Results: Twenty-four patients suspected with mitochondrial myopathy were enrolled initially and 21 were genetically identified. Fourteen patients were found to harbor mitochondrial DNA point mutations (14/21, 66.7%), including m.3243A>G (9/15, 60%), m.3303C>T (2/15, 13.3%), m.3302A>G (1/15, 6.7%), m.3250T>C (1/15, 6.7%), m.3251A>G (1/15, 6.7%), of whom 12 patients presented with progressive proximal mitochondrial myopathy (12/14, 85.7%). Three patients revealed large-scale deletion in blood or muscle tissue (3/21, 14.3%), presenting with Kearns-Sayer syndrome (1/3, 33.3%) or chronic progressive external ophthalmoplegia (2/3, 66.7%). Four patients were found to harbor pathogenic nuclear gene variants (4/21, 19.0%), including five variants in TK2 gene and two variants in SURF1 gene. During the follow-ups up to 7 years, 10 patients developed cardiomyopathy (10/21, 47.6%), 13 patients occurred at least once hypercapnic respiratory failure (13/21, 61.9%), six experienced recurrent respiratory failure and intubation (6/21, 28.6%), eight patients failed to survive (8/21, 38.1%). With nocturnal non-invasive ventilation of BiPAP, three patients recovered from respiratory failure, and led a relative stable and functional life (3/21, 14.3%). Conclusion: Mitochondrial myopathy in children has great clinical, pathological, and genetical heterogeneity. Progressive proximal myopathy is most prevalent. Mitochondrial DNA point mutations are most common. And respiratory failure is a critical risk factor of poor prognosis.

Gene therapeutic strategies and relevant clinical trials in neuromuscular disorder in China.

Neuromuscular disorder is a diverse group of genetic disease, among which Duchenne muscular dystrophy and Spinal muscular atrophy are most common. Recently, the great breakthroughs of gene targeted therapeutic strategies are leading a profound revolution in the standard care of neuromuscular disorders over the world including China. This review will offer an outline of the molecular pathogenesis, clinical progress, critical trials, as well as the challenges of new gene therapy in the treatment of Spinal muscular atrophy and Duchenne muscular dystrophy in China, mainly includes mRNA splicing modulators and adeno-associated virus mediated gene replacement. We hope to highlight some important findings about the critical development of gene therapy in this field, which might be helpful for suggesting potential therapeutic treatment for neuromuscular disease in China.

Clinical and molecular characterization of pediatric mitochondrial disorders in south of China.

Mitochondrial disorders (MDs) are genetic ailments affecting all age groups. Epidemiological data and frequencies of gene mutations in pediatric patients in China are scarce. This retrospective study assessed 101 patients with suspected MDs treated at the Neurology Department of Children's Hospital, Fudan University, in 2011-2017. Mitochondrial (mtDNA) and nuclear (nDNA) samples were assessed by long-range polymerase chain reaction (PCR)-based whole mtDNA sequencing and whole exome sequencing (WES) for identifying pathogenic mutations. Muscle samples underwent various staining protocols and immunofluorescence for detecting selected proteins. Seventeen mutations in the MT-TL1, MT-COX2, MT-ND4, MT, tRNA TRNE, MT-TN, MT-TK, MT-ATP6, MT-ND6, MT-ND3 and MT-CO3 genes were identified in 39 patients, of which m.3243A > G, m.3303C > T, m.8993T > C/G, m.9176T > C, and m.10191T > C were most common. Mitochondrial myopathy and MELAS were most common for m.3243A > G mutation. Four novel mutations were detected, including m.9478insT, m.5666T > C, m.8265T > C, and m.8380-13600 deletion mutations related to Leigh syndrome, mitochondrial myopathy and KSS, respectively. Thirty-three mutations in the TK2, POLG, IBA57, HADHB, FBXL4, ALDH5A1, FOXRED1, TPK1, NDUFAF5, NDUFAF7, NDUFV1, CARS2, PDHA1, and HIBCH genes were identified in 19 patients, including 23 currently unknown. Higher rates of TK2, POLG, IBA57, and HADHB mutations were found in nDNA-mutated MD compared with the remaining individuals. Besides, IBA57 c.286T > C (p.Y96H), TK2 c.497A > T (p.D166V) founder mutations critically contributed to MDs. Comprehensive genomic analysis plays a critical role in pediatric MD diagnosis. These data summarize the relative frequencies of different gene mutations in a large Chinese population, and identified 23 novel MD-associated nDNA and 4 novel mtDNA mutations.

Triazol: a privileged scaffold for proteolysis targeting chimeras.

Current traditional drugs such as enzyme inhibitors and receptor agonists/antagonists present inherent limitations due to occupancy-driven pharmacology as the mode of action. Proteolysis targeting chimeras (PROTACs) are composed of an E3 ligand, a connecting linker and a target protein ligand, and are an attractive approach to specifically knockdown-targeted proteins utilizing an event-driven mode of action. The length, hydrophilicity and rigidity of connecting linkers play important role in creating a successful PROTAC. Some PROTACs with a triazole linker have displayed promising anticancer activity. This review provides an overview of PROTACs with a triazole scaffold and discusses its structure-activity relationship. Important milestones in the development of PROTACs are addressed and a critical analysis of this drug discovery strategy is also presented.

Concise synthesis of 2-methoxyestradiol from 17ß-estradiol through the C(sp2)-H hydroxylation.

A four-step route for the synthesis of 2-methoxyestradiol (5) starting from 17ß-estradiol (1) has been achieved with a 51% overall yield. The key step was the ruthenium-catalyzed ortho-C(sp2)-H bond hydroxylation of aryl carbamates. Using dimethyl carbamate as the directing group, [RuCl2(p-cymene)]2 as the catalyst, PhI(OAc)2 as the oxidant and trifluoroacetate/trifluoroacetic anhydride (1:1) as the co-solvent, the hydroxyl group could be singly installed at the 2-position of 3-dimethylcarbamoyloxyestradiol (2) with 65% yield. Subsequent methylation of hydroxy and removal of dimethyl carbamate afforded 2-methoxyestradiol (5).

A comprehensive database of Duchenne and Becker muscular dystrophy patients (0-18 years old) in East China.

BACKGROUND: Currently, there is no cure for Duchenne and Becker muscular dystrophies (DMD/BMD). However, clinical trials with new therapeutic strategies are being conducted or considered. A comprehensive database is critical for patient recruitment and efficacy evaluation. China has the largest population, yet, no comprehensive database for DMD/BMD is available. Our study registered the data of the DMD/BMD patients in East China. METHODS: A modified registry form of Remudy ( http://www.remudy.jp/ ) was applied to Chinese DMD/BMD patients through the outpatient clinic at Children's Hospital of Fudan University, Shanghai during the period of August 2011 to December 2013. The data included geographic distribution of patients, age at diagnosis, clinical manifestation, genetic analysis and treatment status. RESULTS: 194 DMD and 35 BMD patients were registered. Most patients lived in East China, namely Jiangsu province, Anhui province, Zhejiang province, Jiangxi province, Shanghai, Fujian province and Shandong province. All individuals aged less than 18 years (age limit to a children's hospital). Diagnosis was made for a majority of patients during the age of 3-4 (16.6%) and 7-8 (14.8%) years old. Exon deletion was the most frequent genetic mutations (65.5% and 74.3%) followed by point mutations (14.4% and 11.4%), duplications (9.8% and 8.6%) and small insertion/deletion (9.3% and 2.9%) for DMD and BMD, respectively. 82.5% of DMD registrants were ambulatory, and all the BMD registrants were able to walk. 26.3% of DMD registrants have been treated with steroids. Cardiac functions were examined for 46.4% DMD boys and 45.7% BMD boys and respiratory functions were examined for 18.6% DMD boys and 14.3% BMD boys. Four boys with abnormal cardiac function were prescribed for treatment with cardiac medicine. 33.2% of DMD patients are eligible for exon skipping therapy, and among them 9.2% and 4.3% patients are eligible for skipping exon 51 and 53, respectively. CONCLUSIONS: The database is the first linking accurate genetic diagnosis with clinical manifestation and treatment status of dystrophinopathy patients in East China. It provides comprehensive information essential for further patient management, especially for promotion of international cooperation in developing experimental therapies such as exon skipping and read-through of nonsense mutations targeting a subgroup of DMD patient population.