OBJECTIVE: To explore the clinical phenotypes and genetic characteristics of five children with Lamb-Shaffer syndrome (LAMSHF). METHODS: Five children with LAMSHF diagnosed at the Department of Pediatrics, the First Medical Center of Chinese PLA General Hospital from April 2021 to December 2024 were selected as study subjects. Clinical data of the children was collected. Genomic DNA was extracted from peripheral blood samples of the children and their parents. Whole exome sequencing (WES) was carried out to screen for variants. This study was approved by the Medical Ethics Committee of the Chinese PLA General Hospital (Ethics No.: S2025-411-01). RESULTS: All five children had presented with global developmental delay. Among them, two had manifestations of autism spectrum disorder, two had abnormal electroencephalogram findings, four had abnormal MRI results, and two had ocular abnormalities. WES has detected five novel variants in the SOX5 gene. Among these, c.1771G>C (p.Gly591Arg) was unreported previously. Sanger sequencing confirmed that none of the parents had carried the same variants, suggesting that they were all de novo variants. According to the guidelines from the American College of Medical Genetics and Genomics (ACMG), two nonsense variants and one missense variant were classified as pathogenic, whilst two missense variants were classified as likely pathogenic. CONCLUSION This study has clarified the correlation between the clinical phenotypes of five children with LAMSHF and variants of the SOX5 gene, which expanded the mutational spectrum of the SOX5 gene and provided a basis for the clinical diagnosis and genetic counseling.
Humans ; Male ; Female ; Phenotype ; Child, Preschool ; Child ; SOXD Transcription Factors/genetics* ; Exome Sequencing ; Mutation ; Infant

OBJECTIVE: To explore the genetic variants and phenotypic characteristics of patients with Neurofibromatosis type I (NF1). METHODS: Twenty two NF1 patients who presented at Enze Medical (Center) Group in Taizhou between 2018 and 2024 were selected as the study subjects. Clinical phenotype and family history were collected for the patients. Whole exome sequencing (WES) was carried out for the 22 probands to screen the variants of NF1 gene. Candidate variants were verified by Sanger sequencing of their family members. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: K20230902). RESULTS: The 22 probands were diagnosed between the age of 5 months to 47 years old, and have all shown cafe au lait spots on their skin. Seventeen patients exhibited the phenotype at birth, and 11 had various degrees of neurofibromatosis. Among them, probands 1 and 13 underwent surgical resection of the tumor but had recurred, while proband 12 had amputation due to the huge size and serious impact of the neurofibroma and had no recurrence. Five patients had various degrees of scoliosis. In total 22 germline mutations and one somatic mutation were identified among the 22 families, with 5 variants unreported previously, including 1 nonsense mutation c.1603C>T (Q535*), 3 frameshift mutations [c.7268_7269delCA (Thr2423fs), c.2293del (Arg765Alafs*26), and c.5433_5438delinsGC (Phe1812ArgfsTer50)], and 1 deletion involving exons 41-44 of the NF1 gene and adjacent introns. Proband 13 was found to harbor germline mutation c.6796C>T (Gln2266Ter) and somatic mutation c.1019_1020del (Ser340Cysfs Ter12) in the peripheral blood and tumor tissue, respectively. Among the 22 NF1 probands, 6 had received treatment due to severe illness. Proband 1 had tumor resection in the right upper limb, but was found to have malignant lung tumor and died during follow-up. Proband 12 had multiple recurrence of neurofibroma in the left ring finger. Proband 4 underwent spinal correction surgery due to severe scoliosis. Proband 11 had died due to a central nervous system disease. Among the 22 germline mutations, 6 had led to the occurrence of truncated proteins, which may have a more severe impact on the phenotype. CONCLUSION This study investigated the genetic variants and clinical phenotypes of 22 NF1 families and identified 5 novel variants of the NF1 gene, which has expanded the genotypic and phenotypic spectra of the NF1. Preliminary studies have identified an association between truncated mutations, young age, and severe phenotypes, which may provide important clues for prognosis evaluation. For the clinical diagnosis and treatment of NF1, it is necessary to consider the phenotypic characteristics and genetic testing in combination with genetic counseling and long-term follow-up.
Humans ; Neurofibromatosis 1/pathology* ; Male ; Female ; Pedigree ; Adult ; Child ; Child, Preschool ; Middle Aged ; Adolescent ; Infant ; Young Adult ; Neurofibromin 1/genetics* ; Phenotype ; Asian People/genetics* ; Mutation ; Exome Sequencing ; East Asian People

OBJECTIVE: To explore the clinical and genetic features of a child with Pontocerebellar hypoplasia type 2B (PCH2B) due to compound heterozygous variants of the TSEN2 gene. METHODS: A PCH2B patient presented at Department of Pediatric Neurology, Xiangya Hospital of Central South University in June 2023 was selected as the study subject. Clinical data of the patient were retrospectively analyzed. The patient and her parents were subjected to whole exome sequencing and bioinformatic analysis. Pathogenicity of the candidate variants were classified based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). A literature review was also conducted by searching the China National Knowledge Infrastructure (CNKI), Wanfang Data, and PubMed databases from their establishment to May 2025 using keywords "TSEN2 gene" "PCH2B" and "Pontocerebellar Hypoplasia 2B" to summarize the clinical and genotypic features of patients with PCH2B due to variants of the TSEN2 gene. This study was approved by the Medical Ethics Committee of the Hospital (No.: #202310892). RESULTS: The patient, a 6-year-5-month-old girl, had exhibited severe global developmental delay, developmental regression, autism spectrum disorder, myoclonus of eyelids, feeding difficulty, irritability, progressive microcephaly, esotropia, and hypotonia. MRI showed reduced volume of bilateral cerebellar hemispheres and vermis. Genetic testing revealed that she has harbored compound heterozygous variants of the TSEN2 gene (NM_025265.4), namely c.1054A>T (p.Lys352*) and c.899G>T (p.Ser300Ile), which were inherited from her father and mother, respectively. Both variants were classified as likely pathogenic based on the ACMG guidelines and were previously unreported. Literature review has identified six PCH2B patients with missense, nonsense, frameshift, and splice site variants of the TSEN2 gene. Their main clinical manifestations included global developmental delay, progressive microcephaly, feeding difficulties, irritability, and vermis hypoplasia. Cranial MRI and genetic testing are crucial for definite diagnosis. CONCLUSION The c.1054A>T (p.Lys352*) and c.899G>T (p.Ser300Ile) compound heterozygous variants of the TSEN2 gene probably underlay the pathogenesis in this patient. Above findings has expanded the genotypic and phenotypic spectra of TSEN2-related PCH2B, and offered guidance for genetic counseling for this family.
Child ; Female ; Humans ; Cerebellar Diseases/genetics* ; Exome Sequencing ; Heterozygote ; Mutation

OBJECTIVE: To analyze the clinical phenotype and pathogenic mechanism of the ARSL gene variant in a fetus with nasal bone aplasia. METHODS: A 34-year-old pregnant woman who attended Quzhou Maternal and Child Health Care Hospital on January 3, 2023 was selected as the study subject. Whole exome sequencing (WES) was performed on the fetus. Bioinformatics analysis was carried out to identify and prioritize candidate gene variants, followed by Sanger sequencing for familial validation. A mutant plasmid expression vector was constructed and subsequently transfected into HEK293T cells to preliminarily investigate the pathogenetic mechanism of the identified variant. Additionally, a comprehensive review of literature was conducted to systematically summarize the associated clinical phenotypes. This study was approved by the Medical Ethics Committee of Quzhou Maternal and Child Health Care Hospital (Ethics No.: KY-2023-11). RESULTS: WES revealed that the fetus harbored a c.827del (p.L276Rfs*48) variant of the ARSL gene, for which its mother was heterozygous. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as pathogenic(PVS1+PM2_Supporting). In vitro cellular function studies demonstrated that this variant can result in a substantial decrease in the expression of mutant mRNA, thereby preventing the production of normal ARSL protein. Clinical phenotypes resulting from ARSL gene variants exhibited considerable diversity, with nasal hypoplasia being the most common manifestation. CONCLUSION The c.827del (p.L276Rfs*48) variant of the ARSL gene can lead to degradation of mRNA via the nonsense-mediated mRNA decay pathway, resulting in reduced levels of ARSL protein. The pathogenetic mechanism underlying the ARSL gene variant may be associated with its haploinsufficiency effect.
Humans ; Female ; Pregnancy ; Adult ; Frameshift Mutation ; HEK293 Cells ; Nasal Bone/abnormalities* ; Fetus/abnormalities* ; Exome Sequencing

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with Hereditary spastic paraplegia type 3A (SPG3A) and the genotype-phenotype correlation. METHODS: A three-generation pedigree presented at Huantai Maternal and Child Health Care Hospital in March 2021 was selected as the study subject. Whole-exome sequencing (WES) and pedigree analysis was carried out. Candidate variant was validated by Sanger sequencing of the members from the pedigree. Haplotype analysis was used to trace the origin of the variant, and pathogenicity was rated based on the guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2025-12). RESULTS: A c.1024C>T (p.Pro342Ser) variant of the ATL1 was identified in the four affected members, including the proband, but none of the three unaffected relatives. Haplotype analysis suggested that the variant was derived from the proband's mother and has co-segregated with the disease phenotype. Based on the guidelines of the ACMG, it was classified as likely pathogenic. CONCLUSION The ATL1 c.1024C>T (p.Pro342Ser) variant probably underlay the pathogenesis in this pedigree. Above finding has enriched the mutational spectrum of ATL1 and phenotypic spectrum of SPG3A in the Chinese population, and enabled genetic counseling for this pedigree.
Humans ; Pedigree ; Spastic Paraplegia, Hereditary/genetics* ; Male ; Female ; Asian People/genetics* ; Adult ; Haplotypes ; Membrane Proteins/genetics* ; Exome Sequencing ; GTP-Binding Proteins/genetics* ; Mutation ; Middle Aged ; China ; Genetic Association Studies ; East Asian People

OBJECTIVE: To explore the genotype-phenotype correlation in a Chinese family with structural brain abnormalities due to variant of the TUBB gene. METHODS: A family undergoing prenatal diagnosis at Beijing Obstetrics and Gynecology Hospital in October 2024 was selected as the study subject. Clinical data were collected. Amniotic fluid sample was subjected to chromosomal copy number variation sequencing (CNV-seq). Trio whole-exome sequencing (Trio-WES) was carried out on the amniotic fluid and parental blood samples, and candidate variant was verified by Sanger sequencing. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: 2023-KY-076-01). RESULTS: Both prenatal ultrasound and fetal MRI showed deviation of brain midline, unilateral lateral ventriculomegaly, and bilateral gyral asymmetry. Trio-WES revealed that the fetus has harbored a maternally derived heterozygous missense variant of the TUBB gene [NM_178014.4: c.155A>G (p.N52S)]. Sanger sequencing confirmed that the woman and a previously terminated fetus both harbored the same variant. Both the proband and two fetuses exhibited similar neuroimaging abnormalities including midline deviation and asymmetrical gyri. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as likely pathogenic (PM2_Supporting+PS2_Moderate+PS3). CONCLUSION The heterozygous c.155A>G (p.N52S) variant was the TUBB gene probably underlay the pathogenesis of the structural brain abnormalities in this family. Above findings have expanded the phenotypic spectrum associated with the variant and facilitated the prenatal diagnosis for this family.
Humans ; Female ; Pregnancy ; Prenatal Diagnosis ; Tubulin/genetics* ; Adult ; Brain/diagnostic imaging* ; Male ; Pedigree ; DNA Copy Number Variations/genetics* ; Exome Sequencing ; Genetic Association Studies ; Magnetic Resonance Imaging

OBJECTIVE: To analyze the phenotype and genotype of a neonate with Osteo-oto-hepato-enteric syndrome (O2HE) and review the literature. METHODS: A female neonate diagnosed with O2HE syndrome on December 13, 2024 at the First Affiliated Hospital of Zhengzhou University was selected as the study subject, and her clinical characteristics were analyzed, and pathogenic variants were explored by whole exome sequencing (WES). This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: 2025-KY-1038). RESULTS: The proband, a female infant, was delivered by Cesarean section at 36⁺¹ weeks of gestation. Five days after birth, she had developed severe diarrhea, mild cholestasis, sensorineural hearing loss, and growth retardation. WES revealed that she has harbored novel compound heterozygous variants c.512delA (p.Lys171Serfs*64) and c.698C>A (p.Thr233Asn) of the UNC45A gene, which were inherited from her mother and father, respectively. A total of 8 English papers were retrieved, which involved 16 patients from 14 families. Combined with our case, the 17 patients included 13 (76.5%) females and 4 (23.5%) males. Four patients (23.5%) had consanguineous parents. One case was excluded from further genetic analysis due to co-morbidity with other genetic variants. The primary clinical features included diarrhea (87.5%), cholestasis (81.3%), sensorineural hearing loss (31.3%), bone fragility (37.5%), and developmental delay (50.0%). Bi-allelic compound heterozygous mutations were identified in 12 patients (75.0%), and homozygous variants in 4 (25.0%). These included missense, nonsense, frameshift and deletional variants. The c.710T>C (p.Leu237Pro) variant was identified for 5 times, 3 of which were in homozygote forms. CONCLUSION O2HE syndrome should be suspected in cases with diarrhea, cholestasis, and hearing abnormalities during early postnatal period. Genetic testing facilitate early identification, genetic diagnosis and treatment.
Humans ; Female ; Infant, Newborn ; Male ; Mutation ; Hearing Loss, Sensorineural/genetics* ; Diarrhea, Infantile/genetics* ; Exome Sequencing ; Phenotype ; Fetal Growth Retardation ; Hair Diseases ; Facies

OBJECTIVE: To delineate the clinical and genetic features of a Chinese girl harboring a rare de novo variant of SYNGAP1 associated with Mental retardation, autosomal dominant 5 (MRD5), and to conduct a comprehensive genotype-phenotype correlation analysis within the Chinese population through an extensive literature review. METHODS: A 5-year-old girl presenting with seizures without an obvious cause was enrolled in September 2020. Genomic DNA was extracted from the patient and her parents. Whole exome sequencing (WES) was performed on the proband to identify suspected pathogenic variants based on her clinical phenotype. Sanger sequencing was used for validation, followed by bioinformatic analysis of the variant. Additionally, data from 54 previously reported Chinese cases with SYNGAP1 variants were integrated to summarize the distribution of variant types and clinical characteristics. Ethical approval was obtained from the Ethics Committee of Kunming Children's Hospital (Ethics No.: 2021-03-055-K01). RESULTS: WES identified a heterozygous nonsense variant, SYNGAP1 c.725G>A (p.Trp242*), in the proband. Sanger sequencing confirmed it was a de novo variant. According to the ACMG guidelines, this variant was classified as pathogenic (PVS1+PS2). Based on the clinical manifestations, the patient was diagnosed with MRD5. Bioinformatic analysis suggested that this variant introduces a premature stop codon at tryptophan 242, disrupting the PH domain and leading to the loss of the C2, Ras-GAP, and C-terminal domains. The pooled analysis of Chinese cases revealed that nonsense (38.2%) and frameshift (36.4%) variants were the predominant types. Intellectual disability/developmental delay was present in 100.0% of patients, epilepsy in 83.6%, and autism spectrum disorder in 41.3%. The incidence of epilepsy differed significantly among variant types (P = 0.045). Exons 8 and 15 were identified as mutation hotspots. CONCLUSION This study has identified a SYNGAP1 c.725G>A variant in the Chinese population and confirmed it as a potential cause of MRD5, which expanded the mutational spectrum of this disorder.
Humans ; Female ; Child, Preschool ; Intellectual Disability/genetics* ; ras GTPase-Activating Proteins/genetics* ; Phenotype ; Exome Sequencing ; Genetic Association Studies

OBJECTIVE: To explore the genetic etiology of 46 Chinese pedigrees affected with Hereditary multiple exostoses (HME) and provide genetic counseling and reproductive intervention. METHODS: Whole-exome sequencing and Sanger sequencing were carried out on 87 patients from the 46 pedigrees to analyze the variants of EXT1 and EXT2 genes. Pathogenicity of the variants was assessed based on the guidelines from the American College of Medical Genetics and Genomics and Association for Molecular Pathology (ACMG/AMP). Prenatal diagnosis and preimplantation genetic testing (PGT) were provided for couples with identified pathogenic mutations. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: LL-SC-SG-2014-010). RESULTS: In total 17 and 22 pathogenic variants were respectively identified in the EXT1 and EXT2 genes, among which 5 EXT1 and 12 EXT2 variants were unreported previously. Three patients with no family history were found to harbor de novo variants of the EXT1 gene. Twenty nine couples had opted for PGT or underwent prenatal diagnosis following natural conception, and 17 healthy babies were born. CONCLUSION This study has clarified the genetic etiology of 45 HME pedigrees and identified 17 novel variants, which has enriched the mutational spectrum of the EXT1 and EXT2 genes. Reproductive intervention through PGT and prenatal diagnosis have prevented the recurrence of HME in these families.
Humans ; Female ; Male ; Pedigree ; Exostoses, Multiple Hereditary/diagnosis* ; N-Acetylglucosaminyltransferases/genetics* ; Adult ; Exostosin 1 ; Asian People/genetics* ; Genetic Testing ; Exostosin 2 ; Mutation ; China ; Prenatal Diagnosis ; Pregnancy ; Genetic Counseling ; Preimplantation Diagnosis ; Exome Sequencing ; East Asian People

OBJECTIVE: To investigate the clinical manifestations and genetic etiology of a fetus with Neurodevelopmental disorders with deformed facial features and distal skeletal abnormalities (NEDDFSA). METHODS: Clinical data of a NEDDFSA fetus diagnosed at the Affiliated Women and Children's Hospital Affiliated to Ningbo University in March 2025 was selected as the study subject. Whole-exome sequencing (WES) was carried out on the amniotic fluid and parental peripheral blood samples, and candidate variants was verified by Sanger sequencing. The pathogenicity of candidate variant was rated based on guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: EC2023-094). RESULTS: At 30 weeks of gestation, the fetus was found to have microcephaly, short femur and intrauterine growth restriction. WES revealed that the fetus harbored a de novo heterozygous frameshift variant c.2633dup (p.Gly879ArgfsTer22) of the ZMIZ1 gene, which was rated as pathogenic (PM2_Supporting+PS2_Supporting+PVS1). Combined with 25 cases from the literature, the main manifestations of patients have included intellectual disability, growth retardation and cranio-limb skeletal dysplasia, albeit without clear genotype-phenotype correlation. CONCLUSION The de novo variant c.2633dup (p.Gly879ArgfsTer22) of the ZMIZ1 gene probably underlay the NEDDFSA in this fetus. Genetic testing has enabled accurate prenatal diagnosis and provided evidence for genetic counseling and reproductive guidance of this family.
Humans ; Female ; Pregnancy ; Neurodevelopmental Disorders/genetics* ; Transcription Factors/genetics* ; Fetus/abnormalities* ; Exome Sequencing ; Prenatal Diagnosis