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 genetic basis for a EAST/SeSAME syndrome child featuring epilepsy, ataxia, sensorineural deafness and intellectual disability. METHODS: A child with EAST/SeSAME syndrome who had presented at the Third Affiliated Hospital of Zhengzhou University in January 2021 was selected as the study object. Peripheral blood samples of the child and her parents were collected and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing. RESULTS: Genetic testing revealed that the child has harbored compound heterozygous variants of the KCNJ10 gene, namely c.557T>C (p.Val186Ala) and c.386T>A (p.Ile129Asn), which were inherited from her mother and father, respectively. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were predicted as likely pathogenic (PM1+PM2_Supporting+PP3+PP4; PM1+PM2_Supporting+PM3+PP3+PP4). CONCLUSION The patient was diagnosed with EAST/SeSAME syndrome due to the compound heterozygous variants of the KCNJ10 gene.
Humans ; Child ; Female ; Intellectual Disability/genetics* ; Hearing Loss, Sensorineural/genetics* ; Ataxia ; Genetic Diseases, X-Linked ; Mutation

Arrhythmias, Cardiac ; Genetic Diseases, X-Linked/genetics* ; Gigantism/genetics* ; Heart Defects, Congenital/genetics* ; Humans ; Intellectual Disability/genetics* ; Male ; Neuroblastoma

OBJECTIVE: To explore the genetic basis for a child affected with cerebral creatine deficiency syndrome 1 (CCDS1). METHODS: High-throughput sequencing was carried out to screen pathogenic variant associated with the clinical phenotype of the proband. The candidate variant was verified by Sanger sequencing. RESULTS: High-throughput sequencing revealed that the proband has carried heterozygous c.327delG variant of the SLC6A8 gene, which was verified by Sanger sequencing.Neither parent was found to carry the same variant. CONCLUSION The de novo heterozygous c.327delG variant of the SLC6A8 gene probably underlay the CCDS1 in this child.
Brain Diseases, Metabolic, Inborn/genetics* ; Creatine ; Genetic Testing ; Heterozygote ; Humans ; Mental Retardation, X-Linked ; Mutation

OBJECTIVE: To explore the genetic basis for a pedigree affected with Nance-Horan syndrome. METHODS: Clinical manifestation of the patients was analyzed. Genomic DNA was extracted from peripheral blood samples of the pedigree members and 100 unrelated healthy controls. A panel of genes for congenital cataract was subjected to next-generation sequencing (NGS), and candidate variant was verified by Sanger sequencing and bioinformatic analysis based on guidelines of American College of Medical Genetics and Genomics (ACMG). mRNA expression was determined by reverse transcriptase-PCR (RT-PCR). Linkage analysis based on short tandem repeats was carried out to confirm the consanguinity. RESULTS: A small insertional variant c.766dupC (p.Leu256Profs*21) of the NHS gene was identified in the proband and his affected mother, but not among unaffected members and the 100 healthy controls. The variant was unreported in Human Gene Mutation Database (HGMD) and other databases. Based on the ACMG guideline, the variant is predicted to be pathogenic (PVS1+PM2+PM6+PP4). CONCLUSION The novel variant c.766dupC of the NHS gene probably underlay the X-linked dominant Nance-Horan syndrome in this pedigree.
Cataract/genetics* ; Genetic Diseases, X-Linked ; Humans ; Mutation ; Pedigree ; State Medicine ; Tooth Abnormalities

OBJECTIVE: To explore the genetic pathogenesis of X-linked agammaglobulinemia in two patients for clinical diagnosis and family counseling. METHODS: Data was collected from the patients' family including clinical information, blood immunoglobulin level, as well as classification and subgrouping of B lymphocytes. Gene mutations were screened by whole exome sequencing (WES) through next-generation sequencing (NGS), the result was verified with Sanger sequencing. RESULTS: A BTK c.1627T>C (p.Ser543Pro) variant was found in the pedigree. The phenotype and variant have co-segregated in the pedigree. The variant was not found in population database. The variant has affected in the kinase domain which contained no benign variants and is harmful as predicted through bioinformatic analysis. CONCLUSION BTK c.1627T>C (p.Ser543Pro) is a pathogenic variant contributing to X-linked agammaglobulinemia in this pedigree. Above finding has provided reproduction guidance for this family.
Agammaglobulinaemia Tyrosine Kinase/genetics* ; Agammaglobulinemia/genetics* ; DNA Mutational Analysis ; Genetic Diseases, X-Linked ; Humans ; Mutation ; Pedigree

OBJECTIVE: To report on the clinical features and result of genetic testing for a child featuring immune dysregulation, polyendocrinopathy, enteropathy, X-linked (IPEX) syndrome. METHODS: Clinical records, genetic testing, laboratory investigation and treatment of the child were summarized in addition with a comprehensive review of the literature. RESULTS: The 3-year-old boy was administered due to intractable diarrhea, recurrent infections, liver dysfunction and failure to thrive, though no diabetes or skin disorder was observed. Laboratory testing showed elevated liver enzymes and total IgE, decreased albumin and electrolyte imbalance. Gastrointestinal endoscopy revealed erosion and granules in the duodenum, and edema in the terminal ileum and colon. Biopsies showed villous atrophy in the duodenum and terminal ileum. Genetic testing revealed that the patient has carried a missense c.1087A>G (p.I363V) variant in the exon 10 of the FOXP3 gene. He was treated with enteral and parenteral nutrition, anti infection and Sirolimus, and was waiting for hemopoietic stem cell transplantation. CONCLUSION Although IPEX syndrome usually occur during infancy, it should not be ruled out solely based on the age, and its presentation can be variable. For male children with refractory diarrhea, autoimmune disorder and growth retardation, the diagnosis should be suspected and confirmed by genetic testing.
Child, Preschool ; Diabetes Mellitus, Type 1/genetics* ; Diarrhea/genetics* ; Forkhead Transcription Factors/genetics* ; Genetic Diseases, X-Linked/genetics* ; Genetic Testing ; Humans ; Immune System Diseases/genetics* ; Male ; Mutation ; Polyendocrinopathies, Autoimmune/genetics*

OBJECTIVE: To detect pathogenic variant of the FGD1 gene in a boy with Aarskog-Scott syndrome. METHODS: Genetic variant was detected by high-throughput sequencing. Suspected variant was verified by Sanger sequencing. The nature and impact of the candidate variant were predicted by bioinformatic analysis. RESULTS: The child was found to harbor a novel c.1906C>T hemizygous variant of the FGD1 gene, which has led to conversion of Arginine to Tryptophane at codon 636(p.Arg636Trp). The same variant was found in his mother but not father. Based on the American College of Medical Genetics and Genomics guidelines, the c.1906C>T variant of FGD1 gene was predicted to be likely pathogenic(PM1+PM2+PM5+PP2+PP3+PP4). CONCLUSION The novel c.1906C>T variant of the FGD1 gene may underlay the Aarskog-Scott syndrome in this child. Above finding has enabled diagnosis for the boy.
Child ; Dwarfism ; Face/abnormalities* ; Genetic Diseases, X-Linked ; Genitalia, Male/abnormalities* ; Guanine Nucleotide Exchange Factors/genetics* ; Hand Deformities, Congenital/genetics* ; Heart Defects, Congenital ; Humans ; Male ; Mutation

OBJECTIVE: To explore the genetic basis for a case of recurrent fetal congenital hydrocephalus. METHODS: Next-generation sequencing was carried out for the fetus, the gravida and two of her sisters. RESULTS: The fetus was found to harbor a c.1765T>C (p.Tyr589His) mutation in exon 14 of the L1CAM gene, which was derived from the gravida. CONCLUSION Male fetuses with recurrent hydrocephalus should be subjected to testing of the L1CAM gene to facilitate genetic counseling and prenatal diagnosis.
DNA Mutational Analysis ; Female ; Fetus ; Genetic Diseases, X-Linked ; diagnosis ; genetics ; Humans ; Hydrocephalus ; diagnosis ; genetics ; Male ; Mutation ; Neural Cell Adhesion Molecule L1 ; genetics ; Pedigree ; Pregnancy