OBJECTIVE: To summarize the clinical features and management of two brothers affected with X-linked inhibitor of apoptosis protein (XIAP) deficiency. METHODS: This study retrospectively analyzed the clinical presentations, treatment, and follow-up of two brothers with XIAP deficiency diagnosed at Shanghai Children's Hospital in 2020, and summarized similar cases recorded in databases such as PubMed, Wanfang, Chinese Medical Association Journals, and WIP from January 2006 to November 2024. This study was approved by the Medical Ethics Committee of our hospital (Ethics No.: 2025R128-E01). RESULTS: Patient 1 was the younger brother, who presented at 8 years of age with growth retardation, folliculitis, erythema nodosum, and perineal abscess. Sequencing revealed that he has carried a hemizygous c.566T>C (p.Leu189Pro) variant of the XIAP gene, which was inherited from his mother. He was allergic to infliximab treatment and underwent allogeneic stem cell transplantation (HSCT) in January 2021. During a follow-up of 3 years and 10 months post-transplantation, he showed no gastrointestinal symptoms and had a good outcome. Patient 2 was the elder brother, who presented at 10 years and 6 months of age with growth retardation, rash, and anal fistula. Genetic testing revealed the same variant. He was treated with oral azathioprine but did not have regular follow-ups. At 14-years-and-6-months of age, he had developed severe gastrointestinal infection and hemophagocytic lymphohistiocytosis, which was alleviated after treatment with antibiotics, glucocorticoids, immunoglobulin, and rituximab. He is currently being prepared for HSCT. A total of 13 publications were retrieved, which involved 64 patients from 23 families, with 23 different variants identified. The main clinical manifestations included splenomegaly (34 cases, 53.1%), hemophagocytic lymphohistiocytosis (27 cases, 42.2%), and inflammatory bowel disease or colitis (20 cases, 31.8%). There were significant phenotypic differences among patients from the same family. Thirteen patients (20.3%) underwent HSCT, with a survival rate of 61.5%. CONCLUSION For male children with early onset, poor treatment response, especially those with unexplained splenomegaly and IBD-like symptoms, early genetic testing is recommended. HSCT is a safe and effective treatment for XIAP deficiency. For patients with developmental delay, early onset, and severe IBD phenotype, early transplantation is recommended.
Humans ; Male ; X-Linked Inhibitor of Apoptosis Protein/deficiency* ; Child ; Genetic Diseases, X-Linked/therapy* ; Phenotype ; Siblings ; Retrospective Studies ; Hematopoietic Stem Cell Transplantation

Duchenne muscular dystrophy (DMD) is an X-linked recessive neuromuscular disorder characterized primarily by progressive degeneration and necrosis of skeletal muscle, resulting from mutations in the Dystrophin gene. Patients with DMD typically present with progressive muscle weakness and atrophy during childhood. Currently, available treatment options for DMD remain limited and their efficacy is suboptimal. This review aims to provide a systematic overview of recent advances in therapeutic strategies for DMD, including an analysis of the mechanisms underlying various treatment approaches, outcomes from clinical trials, and their potential clinical applications, in order to inform and guide clinical decision-making.
Muscular Dystrophy, Duchenne/genetics* ; Humans ; Genetic Therapy

Fabry disease, a rare genetic disorder affecting multiple organs, has understudied correlations among enzyme activity, genotype, and clinical manifestations in patients of different sexes with classical and late-onset phenotypes. In this study, clinical data, α-Gal A activity, and GLA gene test results of 311 patients, who were categorized by classical and late-onset phenotypes, ⩽5% and > 5% of the normal mean value of enzyme activity, and truncated and nontruncated mutation groups, were collected. The common clinical manifestations of Fabry disease included acroparesthesia, hypohidrosis/anhidrosis, neuropsychiatric system, and renal and cardiovascular involvement. Multiorgan involvement was higher in males and classical phenotype patients. In both sexes, classical patients commonly presented with acroparesthesia and multiorgan involvement, whereas late-onset patients showed renal, neuropsychiatric, and cardiovascular involvement. Male and classical patients had lower enzyme activity than female and late-onset patients, respectively. Classical males with enzyme activity of ⩽5% of the normal mean level showed higher multiorgan involvement frequency than those with enzyme activity of > 5%, whereas no significant difference was observed among females. Ninety-five gene mutation sites were detected, with significant phenotype heterogeneity in patients with the same mutation. No significant difference in enzyme activity or clinical manifestations was observed between truncated and nontruncated mutations. Overall, male patients with Fabry disease, regardless of classical or late-onset phenotype, have a higher frequency of multiple-organ involvement and lower α-Gal A activity than female patients. α-Gal A activity was closely correlated with clinical symptoms in males but weakly correlated with clinical manifestations in females. The clinical manifestations of patients with the same mutation are heterogeneous, and the correlation between gene mutation and enzyme activity or clinical manifestation is weak.
Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Young Adult ; Age of Onset ; alpha-Galactosidase/metabolism* ; China ; Fabry Disease/enzymology* ; Genotype ; Mutation ; Phenotype ; Sex Factors ; East Asian People/genetics*

Duchenne muscular dystrophy (DMD) is an X-linked recessive myopathy caused by mutations in the dystrophin gene, which is divided into presymptomatic, early ambulatory, late ambulatory, early non-ambulatory, and late non-ambulatory stages according to its disease progression. Some patients experience non-progressive cognitive developmental delays in the presymptomatic stage. DMD patients gradually develop osteoporosis, cardiomyopathy, decreased respiratory function, delayed puberty, and gastrointestinal symptoms as the disease progresses. The required multidisciplinary management strategies vary across different disease stages. To standardize the multidisciplinary management of DMD, we established the DMD Guideline Writing Committee under the authorization of Chinese Medical Association Rare Disease Branch. Combined with the questions raised by patients in multiple consultations, neuromuscular experts drafted the DMD guidelines based on published clinical evidence, current practices, and expert recommendations. A consensus was reached on the best-practice recommendations for DMD management after extensive consultations with specialists from multiple relevant disciplines. The resulting recommendations have been endorsed by Chinese Medical Association Rare Disease Branch. This guideline provides practical and reasonable recommendations for all healthcare professionals and caregivers involved in DMD management, ensuring that patients can receive high-standard medical treatment and care across our country, which also serves as a reference for government staff involved in DMD management.
Humans ; Muscular Dystrophy, Duchenne/therapy* ; China

OBJECTIVE: To explore the results of four types of Urea cycle disorders (UCDs) in newborns from the Xuzhou region, assess the efficacy of newborn screening by tandem mass spectrometry (MS/MS), and analyze their genetic characteristics. METHODS: A retrospective analysis was performed using tandem mass spectrometry to screen for inherited metabolic disorders in 691 712 newborns at the Maternal and Child Health Care Hospital of Xuzhou from November 2015 to December 2023. Ten children (cases 1-10) were diagnosed with Ornithine transcarbamylase deficiency (OTCD), Carbamoylphosphate synthase 1 deficiency (CPS1D), Arginase deficiency (ARGD), and Argininosuccinate synthase deficiency (ASSD) based on MS/MS and genetic testing. This study was approved by the Medical Ethics Committee of Xuzhou Maternity and Child Health Care Hospital (Ethics No.XZFY2024-051K-01J). RESULTS: A total of 691 712 neonates were screened for UCDs using MS/MS, which identified 1 237, 1 237, 510, and 1 009 initial positive cases for OTCD, CPS1D, ASSD, and ARGD, respectively. After genetic testing, 1 case of OTCD, 1 case of CPS1D, 1 case of ASSD, and 7 cases of ARGD were confirmed. The overall positive predictive value for these four UCDs was 0.362%. Among the 10 diagnosed UCD cases, four novel variants were identified, which included OTC: c.1024C>A (p.L342M) and ASS1: c.826A>G (p.M276V), c.695C>T (p.P232L) and c.694C>T (p.P232S). Bioinformatic analysis has rated these as variants of uncertain clinical significance or likely pathogenic based on guidelines from the American College of Medical Genetics and Genomics (ACMG). CONCLUSION The incidence of four UCDs in neonates from the Xuzhou area is relatively low, and there is a correlation between genetic variants and clinical phenotypes. For novel variants with uncertain clinical significance or suspected pathogenicity, their pathogenicity should be clarified in conjunction with clinical and biochemical indicators. The four novel pathogenic variants of UCDs identified in this study have enriched the mutational spectrum of UCDs-associated genes in the Xuzhou region.
Humans ; Infant, Newborn ; Tandem Mass Spectrometry/methods* ; Urea Cycle Disorders, Inborn/diagnosis* ; Neonatal Screening/methods* ; Genetic Testing/methods* ; Female ; Retrospective Studies ; Male ; Ornithine Carbamoyltransferase Deficiency Disease/diagnosis* ; Mutation ; Carbamoyl-Phosphate Synthase (Ammonia)/genetics* ; Ornithine Carbamoyltransferase/genetics*

OBJECTIVE: To analyze the clinical characteristics and genetic etiology of a child with Christianson syndrome (CS). METHODS: A 1-year-and-5-month-old boy with CS diagnosed at the First Affiliated Hospital of Zhengzhou University in April 2021 was selected as the study subject. Clinical data were retrospectively analyzed. Peripheral blood samples were obtained from the child and his parents, followed by genomic DNA extraction and whole exome sequencing (WES). Candidate variant was validated by Sanger sequencing. This study has been approved by the Medical Ethics Committee of the Hospital of Zhengzhou University (Ethics No. 2024-KY-1103-001). RESULTS: The child has manifested with seizures, microcephaly, and global developmental delay. WES revealed that he has harbored a novel de novo hemizygous nonsense variant of the SLC9A6 gene, namely c.1014G>A (p.W338*). Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as pathogenic. CONCLUSION The hemizygous c.1014G>A nonsense variant of the SLC9A6 gene probably underlay the pathogenesis in this child. Above discovery has expanded mutational spectrum of the SLC9A6 gene and enabled definite diagnosis of the child.
Humans ; Male ; Infant ; Microcephaly/genetics* ; Spasms, Infantile/genetics* ; Sodium-Hydrogen Exchangers/genetics* ; Exome Sequencing ; Intellectual Disability/genetics* ; Genetic Diseases, X-Linked/genetics* ; Mutation ; Seizures/genetics* ; Ataxia ; Epilepsy ; Ocular Motility Disorders

OBJECTIVE: To explore the genetic etiology for a Chinese pedigree affected with X-linked cardiac valve dysplasia (CVDPX) and congenital chronic pseudo intestinal obstruction (CIIPX). METHODS: A pedigree presented at the First Hospital of Lanzhou University for CVDPX combined with CIIX was selected as the study subject. Whole exome sequencing (Trio-WES) was carried out, and the candidate variant was verified by Sanger sequencing. This study has been approved by the Medical Ethics Committee of the First Hospital of Lanzhou University (Ethics No. LDYYSZLLKH2024-15). RESULTS: Both the proband and his affected younger brother were found to harbor a hemizygous c.443A>G (p.Tyr148Cys) variant of the FLNA gene, for which their mother was heterozygous and their father was not a carrier, suggesting an X-linked recessive inheritance pattern. The variant was not recorded in the OMIM and ClinVar databases, and was determined to be likely pathogenic (PM2+PS4+PP2+PP3) based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). The patients had presented with typical CVDPX/CIIPX phenotype, including multiple valve dysplasia and chronic pseudo intestinal obstruction, in addition with gallbladder wall edema and thickening. Bioinformatic analysis showed that the variant site is highly conserved, and multiple algorithms had predicted its pathogenicity. CONCLUSION This study confirmed the diagnosis of CVDPX/CIIX in a Chinese pedigree, expanded the phenotype spectrum of FLNA gene variants, and provided a basis for genetic counseling and prenatal diagnosis for the pedigree.
Adult ; Female ; Humans ; Male ; Exome Sequencing ; Filamins/genetics* ; Genetic Diseases, X-Linked/genetics* ; Heart Defects, Congenital/genetics* ; Heart Valve Diseases/genetics* ; Pedigree ; East Asian People/genetics*

OBJECTIVE: To explore the clinical, genetic, therapeutic and prognostic characteristics of two children with Lesch-Nyhan syndrome (LNS) in order to enhance understanding of this disease and formulate more effective therapeutic strategies. METHODS: Clinical data were collected from two children clinically diagnosed with LNS who were treated at Anhui Provincial Children's Hospital from April 2023 to January 2024. Data were retrospectively collected and included clinical manifestations (symptoms, signs, laboratory and imaging findings), treatment course, and results of follow-up. Peripheral venous blood samples were obtained from child 1 and his parents. Whole-exome sequencing (WES) was performed. Candidate variants were validated by Sanger sequencing. Standard bioinformatic analysis of the raw WES data was conducted, including quality control, alignment, variant calling, and annotation. Candidate pathogenic variants were filtered using population frequency databases (e.g., gnomAD), disease databases (e.g., OMIM, ClinVar), and multiple in silico pathogenicity prediction tools (e.g., SIFT, PolyPhen-2, CADD). Phenotype matching was integrated using Human Phenotype Ontology (HPO) terms. Pathogenicity classification of variants was performed according to the American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines for the Interpretation of Sequence Variants (2015). This study was approved by the Medical Ethics Committee of Anhui Children's Hospital, Children's Hospital of Fudan University (Ethics No.: EYLL-2014-027). RESULTS: Child 1, a 4-year-old boy, had presented with developmental delay for over 3 years, accompanied by abnormal postures and involuntary lip-biting. Physical examination revealed limb dystonia, anxious expression, lower lip damage, and communication difficulties. Laboratory tests showed hyperuricemia and renal stones. Genetic testing identified a hemizygote variant of the HPRT1 gene, c.135G>T (p.Arg45Ser), inherited from an asymptomatic carrier mother, which confirmed the diagnosis of LNS. This variant was absent from population databases (gnomAD, 1000 Genomes, dbSNP). Protein function prediction tools consistently indicated it as a pathogenic or likely pathogenic variant (SIFT, PolyPhen-2, CADD, and REVEL scores all reached pathogenic thresholds). Protein structural modeling revealed that the variant may disrupt the hydrogen-bonding network compromising the tetramer stability. ACMG classification designated it as likely pathogenic (PM1+PM2_Supporting+PM5+PP3). The patient was treated with benhaxol hydrochloride, baclofen, and clonazepam to improve his neurological symptoms, in addition with treatment with febuxostat from the Nephrology Department to manage his purine metabolism. After one year of follow-up, the patient's abnormal posture showed slight improvement, self-injurious behavior persisted but was managed with protective gloves, blood uric acid levels normalized, and renal stones decreased. Case 2, a 13-year-old boy, was hospitalized to the Nephrology Department due to urinary tract infection. Following successful control of the infection, his limb dystonia has worsened, leading to his transfer to the Neurology Ward. The patient had a history of delayed motor and language development, abnormal postures, and lip-biting self-injurious behavior, with elevated blood uric acid levels, leading to the diagnosis of LNS. His parents had declined genetic testing due to financial constraints. Following discharge, the patient did not adhere to the prescribed medication regimen or attend scheduled outpatient visits. The patient had died by the time of the 4-month follow-up contact. CONCLUSION Variants of the HPRT1 gene probably underlay the LNS in the two children, and the HPRT1 is the only known pathogenic gene for LNS. Early genetic diagnosis, strict adherence to multidisciplinary comprehensive treatment, and intensive intervention for self-injurious behaviors are crucial for improving the quality of life and prolonging the survival of children with LNS.
Humans ; Male ; Lesch-Nyhan Syndrome/diagnosis* ; Exome Sequencing ; Child, Preschool ; Phenotype ; Infant ; Child ; Female ; Retrospective Studies ; Mutation

OBJECTIVE: To assess the value of combined detection strategies using multiple technologies for the genetic testing and prenatal diagnosis for pedigrees affected with Duchenne muscular dystrophy (DMD) for optimizing genetic counseling and reproductive guidance. METHODS: This study has involved 142 subjects from 65 suspected DMD families who had visited the First Affiliated Hospital of Chongqing Medical University from January 2018 to December 2023. A combination of multiple ligation-dependent probe amplification (MLPA), quantitative fluorescence PCR, and next-generation sequencing (NGS) was used. After confirming the genetic diagnosis of the probands, prenatal diagnosis was provided for carrier mothers. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2021-264). RESULTS: Among the 142 subjects tested, 73 cases of large deletions/duplications and 15 cases of small variants of the DMD gene were detected. The hotspot regions for the variants were exons 45 to 55. A total of 41 variant types were identified, of which 3 were previously unreported. In 19 families with suspected patients, 7 exonic deletions, 2 exonic duplications, and 3 small variants were identified. Prenatal diagnosis was performed on 48 fetuses from 46 families, revealing 16 affected male fetuses (including 12 with deletion variants, 2 with duplication variants, and 2 with small variants). Seven carrier females were identified among the 16 female fetuses (including 6 with deletions and 1 with duplication). Among the couples with an affected fetus, 16 had opted to terminate the pregnancy, while the parents of 32 fetuses had chosen to continue with the pregnancy. In families undergoing prenatal diagnosis, 53 (79.1%) pregnant women and their family members were found to carry mutations of the DMD gene. CONCLUSION The combined detection strategy of MLPA, qPCR, and NGS can encompass large deletions/duplications and small variants of the DMD gene, providing timely and accurate prenatal diagnosis for families affected by DMD. In conjunction with genetic counseling, this can effectively reduce the risk of producing affected offspring, which is crucial for the prevention and control of this disease.
Humans ; Muscular Dystrophy, Duchenne/diagnosis* ; Prenatal Diagnosis/methods* ; Female ; Male ; Pregnancy ; Pedigree ; Genetic Testing/methods* ; Dystrophin/genetics* ; Adult ; Genetic Counseling ; High-Throughput Nucleotide Sequencing/methods* ; Exons

Humans ; Fabry Disease/therapy* ; Hypertrophy, Left Ventricular/diagnosis* ; Diagnosis, Differential