Hereditary myopathy with early respiratory failure is a titin （TTN）-related myopathy caused by mutations in the A-band of the TTN gene.This condition is characterized by distinctive clinical and pathological features， as well as a typical skeletal muscle involvement pattern. We report a 43-year-old male patient with progressive distal limb weakness over the past three years. The initial symptom was difficulty in lifting both feet， followed by difficulty in extending the dorsum of both hands one year later. However， the patient never experienced dyspnea. The patient's past medical history was unremarkable， and there was no family history of inherited diseases.His parents were healthy. Physical examination revealed wrist drop and noticeable atrophy of the tibialis anterior in both calves. Muscle strength in the lower limbs was graded at 4 for proximal muscles and 2 for distal muscles.Laboratory tests showed a creatine kinase level of 375U/L（normal range：50~310）. Electromyography revealed myogenic injury in the bilateral tibialis anterior and the right extensor digitorum communis. Magnetic resonance imaging of the muscles showed isolated involvement of the semitendinosus muscle with severe fatty infiltration， along with significant fatty degeneration of the anterior calf muscles. Muscle biopsy of the proband showed subsarcolemmal “necklace-like” cytoplasmic bodies and the “erasure” phenomenon on NADH enzyme histochemistry. Both electrocardiogram and echocardiography showed no abnormalities. Exome sequencing of the proband identified a missense mutation in the TTN gene， c.95358C>G， p.Asn31786Lys. Sanger sequencing confirmed that the mutation was absent in both parents of the proband， indicating a de novo mutation.

Objective:To investigate the clinical characteristics of urea cycle disorder (UCD), the efficacy and safety of glyceryl phenylbutyrate (GPB) therapy in pediatric patients with UCD.Methods:This study was a retrospective, single-arm, multicenter clinical study. The clinical data of 20 pediatric patients with UCD who received GPB treatment at 9 hospitals nationwide between December 2021 and August 2024 were collected. The clinical manifestations, laboratory results, and molecular genetic characteristics were analyzed, ammonia levels and other laboratory results were evaluated pre-post GPB therapy by paired t-tests or Wilcoxon tests. Results:Among the 20 pediatric patients with UCD, there were 8 males and 12 females, and the onset age was 2.8 (1.4, 5.7) years. The ammonia levels were 174 (125, 342) μmol/L at first onset. The symptoms included vomiting in 6 cases, drowsiness in 5 cases, epilepsy in 5 cases, developmental delay in 5 cases, psychiatric and behavioral abnormalities in 3 cases, and lethargy in 1 case, and 18 cases exhibited abnormal liver function. Twenty cases included 6 UCD subtypes, with 11 cases being ornithine transcarbamylase deficiency. A total of 27 variants were identified, 11 (41%) of which were novel. The age of patients who began GPB therapy was 4.0 (1.5, 6.6) years. Ten cases stopped GPB after 4.2 (3.4, 5.3) months, with 4 patients undergoing liver transplantation and 6 discontinuing for financial reasons. The remaining ten patients continued GPB therapy for 11.6 (8.6, 14.0) months. The duration of GPB treatment was 6.0 (4.2, 12.3) months, at the final visit, the levels of ammonia, platelets and aspartate aminotransferase were lower compared to those of pre-treatment (all P<0.05). The serum albumin level was higher than that of pre-treatment ( P=0.016). Two patients suffered only one episode of acute hyperammonaemia, with ammonia levels of 232 and 141 μmol/L, respectively. Nine cases experienced adverse effects potentially related to GPB, decreased appetite in 6 cases, vomiting in 3 cases, abnormal skin oil odor in 2 cases, somnolence, fatigue and diarrhea each in 1 case, with symptoms improved within 6 (3, 10) days. Conclusions:UCD primarily manifests with neurological and gastrointestinal symptoms, and early diagnosis of UCD could be achieved through the analysis of ammonia. GPB may effectively reduce ammonia levels in UCD pediatric patients, with favorable safety and tolerability.

Objective:To investigate the clinical characteristics of urea cycle disorder (UCD), the efficacy and safety of glyceryl phenylbutyrate (GPB) therapy in pediatric patients with UCD.Methods:This study was a retrospective, single-arm, multicenter clinical study. The clinical data of 20 pediatric patients with UCD who received GPB treatment at 9 hospitals nationwide between December 2021 and August 2024 were collected. The clinical manifestations, laboratory results, and molecular genetic characteristics were analyzed, ammonia levels and other laboratory results were evaluated pre-post GPB therapy by paired t-tests or Wilcoxon tests. Results:Among the 20 pediatric patients with UCD, there were 8 males and 12 females, and the onset age was 2.8 (1.4, 5.7) years. The ammonia levels were 174 (125, 342) μmol/L at first onset. The symptoms included vomiting in 6 cases, drowsiness in 5 cases, epilepsy in 5 cases, developmental delay in 5 cases, psychiatric and behavioral abnormalities in 3 cases, and lethargy in 1 case, and 18 cases exhibited abnormal liver function. Twenty cases included 6 UCD subtypes, with 11 cases being ornithine transcarbamylase deficiency. A total of 27 variants were identified, 11 (41%) of which were novel. The age of patients who began GPB therapy was 4.0 (1.5, 6.6) years. Ten cases stopped GPB after 4.2 (3.4, 5.3) months, with 4 patients undergoing liver transplantation and 6 discontinuing for financial reasons. The remaining ten patients continued GPB therapy for 11.6 (8.6, 14.0) months. The duration of GPB treatment was 6.0 (4.2, 12.3) months, at the final visit, the levels of ammonia, platelets and aspartate aminotransferase were lower compared to those of pre-treatment (all P<0.05). The serum albumin level was higher than that of pre-treatment ( P=0.016). Two patients suffered only one episode of acute hyperammonaemia, with ammonia levels of 232 and 141 μmol/L, respectively. Nine cases experienced adverse effects potentially related to GPB, decreased appetite in 6 cases, vomiting in 3 cases, abnormal skin oil odor in 2 cases, somnolence, fatigue and diarrhea each in 1 case, with symptoms improved within 6 (3, 10) days. Conclusions:UCD primarily manifests with neurological and gastrointestinal symptoms, and early diagnosis of UCD could be achieved through the analysis of ammonia. GPB may effectively reduce ammonia levels in UCD pediatric patients, with favorable safety and tolerability.

Objective:To analyze the disease spectrum of lysosomal storage disorders(LSDs) and explore the prevalent distributions of different LSD types in one center in Shanghai.Methods:A retrospective analysis was made.A total of 5 476 suspected LSD patients, including 3 415 males and 2 061 females, with a median age of 4 years(1 day to 72 years), were collected from Xinhua Hospital, Shanghai Jiaotong University School of Medicine from August 2008 to May 2022.The activity of different lysosomal enzymes was detected by fluorescent and biochemical methods.Results:A total of 1 520 patients were diagnosed with LSDs, including 972 males and 548 females, with a median age of 4 years(1 day to 59 years), involving 19 different subtypes.Mucopolysaccharidosis(MPS) was the most common type among LSDs, with a frequency of 45.46%(691/1 520), followed by sphingolipidoses [33.88%(515/1 520)] and glycogen storage disease type Ⅱ [16.05%(244/1 520)] successively.MPS Ⅱ was the most common type in MPS, with a frequency of 45.73%(316/691), followed by MPS ⅣA [22.87%(158/691)]. Niemann-Pick A/B, Gaucher, and Krabbe diseases were common in Sphingolipidoses patients, with frequencies of 37.09%(191/515), 34.37%(177/515), and 10.29%(53/515), respectively.Conclusions:LSDs are common genetic metabolic diseases, especially MPS and sphingolipidoses.Newborn screening for LSDs should be carried out timely so that the patients can be treated early and their prognosis can be improved.

21 hydroxylase deficiency (21-OHD), the most common form of congenital adrenal hyperplasia, is caused by defects in CYP21A2 gene, which encodes the cytochrome P450 oxidase (P450C21) involved in glucocorticoid and mineralocorticoid synthesis. The diagnosis of 21-OHD is based on the comprehensive evaluation of clinical manifestation, biochemical alteration and molecular genetics results. Due to the complex structure of CYP21A2, special techniques are required to perform delicate analysis to avoid the interference of its pseudogene. Recently, the state-of-the-art diagnostic methods were applied to the clinic gradually, including the steroid hormone profiling and third generation sequencing. To standardize the laboratory diagnosis of 21-OHD, this consensus was drafted on the basis of the extensive knowledge, the updated progress and the published consensuses and guidelines worldwide by expert discussion organized by Rare Diseases Group of Pediatric Branch of Chinese Medical Association, Medical Genetics Branch of Chinese Medical Doctor Association, Birth Defect Prevention and Molecular Genetics Branch of China Maternal and Child Health Association. and Molecular Diagnosis Branch of Shanghai Medical Association.
Child ; Humans ; Adrenal Hyperplasia, Congenital/genetics* ; Steroid 21-Hydroxylase/genetics* ; Consensus ; China ; Clinical Laboratory Techniques ; Mutation

Neonatal screening is one of the crucial parts of the tertiary prevention strategy to reduce congenital disability. Traditional neonatal screening, mainly focusing on genetic metabolic diseases, has limitations in disease types and requires genetic testing for further validation and accurate typing. Currently, conducting genetic screening based on biochemical metabolite screening has become the trend in neonatal screening. This article synthesizes the current state of neonatal genome screening at home and abroad. Herein, the comprehensive concepts of "SNV Plus" (single nucleotide variation plus) and "CNV Plus" (copy number variation plus) have been proposed to develop a new technology that can detect the gene structure of SNV and CNV simultaneously and improve the level of neonatal genome screening based on characteristics of the pathogenic gene structure.
DNA Copy Number Variations ; Humans ; Infant, Newborn ; Neonatal Screening ; Nucleotides

Newborn screening is an effective measure for early detection and early treatment of rare genetic diseases. Among the three-level preventive measures to reduce birth defects, newborn screening has a significant preventive effect, and continues to develop with the advancement of new therapies and new technologies. Newborn screening is also relatively more reliable to obtain data on the prevalence of rare diseases. This article introduces the history and current status of neonatal screening for newborn hereditary metabolic disease in China, presents the disease spectrum and prevalence of 7 819 662 cases of neonatal screening by tandem mass spectrometry, and proposes 12 rare diseases as the primary targeting diseases for newborn screening by tandem mass spectrometry in China. At last, the article raises and discusses the issues of requirement for technology development and ethics of newborn screening.

Objective:To explore the clinical characteristics, genotypes and long-term outcomes of individuals with 3-methylglutaconic aciduria.Methods:The clinical features, biochemical data, genetic test results and treatment outcomes of six children with 3-methylglutaconic aciduria admitted to the Department of Endocrinology, Genetics and Metabolism, Xinhua Hospital from February 2017 to February 2019 were retrospectively analyzed and the Gesell developmental diagnosis schedule was performed to evaluate the development of four patients.Results:Among 6 children with 3-methylglutaconic aciduria 2 were males and 4 were females.Four cases had 3-methylglutaconic aciduria type Ⅰ and 2 cases had 3-methylglutaconic aciduria with deafness,encephalopathy, and Leigh-like syndrome. Five of 6 patients were detected by newborn screening among whom 4 remained asymptomatic, and only one had a postmortem diagnosis. Among them, 4 patients remained asymptomatic, while two presented with clinical symptoms such as jaundice and dyspnea and the age of disease onset was 1 and 2 days respectively. The concentration of 3-methylglutaconic acid in urine of all affected individuals was between 22.38 and 77.09 mmol/molCr, which was above the normal value. Genetic tests were performed for all patients. Eleven variants were identified in 2 genes, of which 10 variants were novel and only c.442C>T p.(R148X) has been previously reported; Seven variants (c.656-2delA, EX5-EX6 Del, c.942+3A>G, c.373C>T p.(R125W), c.895-3C>G, c.667C>T p.(R223X) and c.894+5G>A) were in AUH gene. The others (c.548G>A p.(R138Q), c.442C>T p.(R148X), c.1339C>T p.(R447X) and c.973dupA p.(M325Nfs*5) were in SERAC1 gene. After being treated with leucine diet restriction and L-carnitine, 4 patients with AUH gene variation who were from asymptomatic phase developed normally, whereas those 2 patients with SERAC1 gene variation had a poor prognosis. During the follow-up, 2 patients exhibited varying degrees of psychomotor retardation, the rest had normal course of development.Conclusions:There are significant clinical heterogeneities among individuals with 3-methylglutaconic aciduria. The most common pathogenic variants are splicing variations, followed by nonsense, missense and frameshift mutations. Leucine-free diet and oral L-carnitine therapy are effective for some patients. Newborn screening is essential for early diagnosis and improvement of prognosis.

Objective:To analyze the pathological features of facioscapulohumeral muscular dystrophy (FSHD). For better characterization of inflammatory response in FSHD, we performed histochemical morphological analysis for FSHD and polymyositis (PM) muscle biopsies.In order to provide a reference for guide targeted therapeutic interventions.Methods:The clinical and myopathological data of 30 patients with FSHD from January 2006 to January 2019 in the Sixth Hospital of Shanxi Medical University and the first hospital of Jilin University were retrospectively analyzed. The patients were divided into non-inflammatory infiltration group (16 cases) and inflammatory infiltration group (14 cases) according to the presence or absence of inflammatory cell infiltration. For better characterization of inflammatory response in FSHD, we performed histochemical morphological analysis for two groups of muscles: FSHD and PM muscle biopsies, using Image-Pro plus bioanalytical software.Results:In 30 cases of FSHD, 14 cases showed intramuscular and interstitial inflammatory cell infiltration, especially around the blood vessels. Immunohistochemical staining confirmed that the infiltration of inflammatory cells was mainly CD4 + T lymphocytes. Morphometric analysis showed that there were no significant differences in muscle fiber surface area, density, diameter, inflammatory cell infiltration, regeneration and necrosis between FSHD patients and PM patients ( P>0.05). The total area of myointerstitium in FSHD group was significantly larger than that in PM group ( P=0.03). Conclusions:The pathological morphometric analysis showed that the proliferation of interstitial connective tissue in FSHD inflammatory cell infiltration group was significantly more than that in PM group. Clinicians can identify the two from pathology and provide help for clinical practice.

Objective To explore the clinical feature,genetic variant and clinical outcome of patients with cblA-type methylmalonic acidemia (MMA).Methods Clinical manifestations,therapeutic schedule and prognosis of 12 patients with cblA-type MMA were analyzed.MMAA gene variants were analyzed for all patients and their parents.Results Vomiting,dyspnea and drowsiness were the major clinical features of cblA-type MMA.Eleven patients were vitamin B12-responsive.After treatment,the blood level of propionylcarnitine,ratio of propionylcarnitine/acetylcarnitine,urine level of methylmalonic acid and methylcitric acid have decreased significantly (P＜0.05).Follow-up study showed that 8 patients (66.7％)had normal development,while the rest (33.3％) remained to have various level of mental or movement delay.Fourteen MMAA gene variants were detected,with c.365T＞C (p.L122P) being the most common (29.2％).Six novel variants,including c.54delA (p.A19Hfs * 43),c.275G＞A (p.G92V),c.456delT (p.G153Vfs* 8),c.667dupA (p.T223Nfs* 4),c.1114C＞T (p.Q372X) and c.1137_1138delCA (p.F379Lfs * 27) were found.Conclusion The main clinical manifestations of patients with cblA-type of MMA include vomiting,dyspnea and drowsiness.Most patients are vitamin B12-responsive.c.365T＞C is a potential hot spot variant of MMAA gene in China.