Objective:To explore the clinical phenotype and genetic etiology for seven children with CHARGE syndrome (CS).Methods:Clinical data of 7 children with CS diagnosed between March 2020 and December 2022 at the Children′s Hospital Affiliated to Zhengzhou University were analyzed. Genomic DNA was extracted from peripheral blood samples from the children and their parents, and subjected to whole exome sequencing. Candidate variants were verified by Sanger sequencing and pathogenicity analysis. This study was approved by the Medical Ethics Committee of the Children′s Hospital Affiliatedto Zhengzhou University (Ethics No. 2024-K-023).Results:The ages of the children had ranged from 1 day after birth to 12 years old, and all of them had shown growth retardation. The reasons for their admission had included postnatal breathing, swallowing and feeding difficulties in five cases. One child was found to have abnormal external genitalia in conjunct with hearing impairment, whilst another child had shown no secondary sexual characteristics during puberty. All of the children were found to harbor CHD7 gene variants, which included 3 nonsense variants, 2 frameshifting variants and 2 missense variants, i. e., c. 6292C>T (p.R2098*), c.2754G>A (p.W918*), c. 469C>T (p.R157*), c. 3308T>A (p.V1103D), c. 7111delC (p.Q2371Kfs), c. 6023delA (p.D2008Vfs) and c. 3565C>T (p.R1189C). All of the variants were de novo in origin. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c. 3308T>A (p.V1103D) and c. 3565C>T (p.R1189C) variants were rated as likely pathogenic (PS2+ PM2_Supporting+ PP3), whilst the remainders were rated as pathogenic (PVS1+ PS2+ PM2_Supporting). Conclusion:There is strong clinical and genetic heterogeneity in CS. Early genetic testing may facilitate accurate diagnosis. The detection of novel variants has expanded the phenotypic spectrum of CS and the mutational spectrum of the CHD7 gene.

Objective:To clarify the genetic diagnosis of two children with ring chromosome 18 and explore their mechanisms and clinical phenotypes.Methods:Two patients treated at the Children′s Hospital of Henan Province respectively in June 2022 and March 2023 were selected as the study subjects. Genetic testing and diagnosis were carried out through copy number variation sequencing (CNV-seq), G-banded chromosomal karyotyping, and whole exome sequencing (WES). This study was approved by the Children′s Hospital of Henan Province (Ethics No. 2023-K-075).Results:Child 1 had mainly manifested developmental delay, white matter hypoplasia, type 1 diabetes mellitus, and micropenis. He was found to have a chromosomal karyotype of 46, XY, r(18)(p11.21q22.1)[40]/46, XY[7], and CNV-seq results showed that he has a 14.86 Mb deletion at 18p11.21p11.32 and a 14.02 Mb deletion at 18q22.1q23. Child 2 had peculiar facial features, delayed white matter myelination, developmental delay, atrial septal defect, severe sensorineural deafness, and congenital laryngeal stridor. He was found to have a chromosomal karyotype of 46, XY, r(18)(p11.2q23). CNV-seq result proved that he had a 14.86 Mb deletion at 18p11.21p11.32 and a 20.74 Mb deletion at 18q21.32q23. WES has failed to detect single nucleotide variants (SNVs) in either child, but revealed a large segmental deletion at chromosome 18 in both of them.Conclusion:Both children were diagnosed with ring chromosome 18 syndrome. The different size of the deletional fragments in the 18q region and mosaicism of ring chromosome 18 in child 1 may underlay the variation in their clinical phenotypes. The type 1 diabetes mellitus and micropenis noted in both children are novel features for ring chromosome 18 syndrome.

Objective:To investigate the correlation between clinical phenotypes and genetic characteristics of children with ring chromosomes (RCs).Methods:Case series study.The clinical data of 11 434 children who received treatment and peripheral blood chromosome karyotype detection in Henan Children′s Hospital from October 2008 to October 2023 due to growth retardation, intellectual impairment or congenital malformation were analyzed retrospectively.A total of 25 children with RCs were selected.Their age at diagnosis, karyotype distribution, clinical manifestations, and genetic detection results were analyzed.Results:RCs were detected in 25 out of 11 434 children, with a detection rate of 0.21%.The genome-wide copy number variation (CNV) analysis was performed on 7 RCs cases, and it found that pathogenic variation existed in all of them.Among the 25 RC cases (11 males and 14 females of social gender), the age at diagnosis ranged from 2 months to 14 years; there were 20 autosomal rings and 5 sex chromosome rings; 13 cases had chimeric karyotypes, and 12 cases had non-chimeric karyotypes.Most of the 25 children showed clinical manifestations of mental or developmental retardation, and some also presented with specific clinical manifestations, such as short stature, congenital malformation, and epilepsy.Conclusions:The pathogenesis of RCs is complex.The clinical manifestations are determined by both RCs syndrome and specific phenotypes caused by the dose effect and exhibit high heterogeneity, so it is easy to miss or misdiagnose.The combined application of cellular and molecular genetic detection technology can facilitate early diagnosis and treatment of RCs, and the correlation analysis of phenotypes and genetic characteristics can provide guidance for genetic counseling.

OBJECTIVE: To define the nature and origin of a chromosomal aberration in a child with unexplained growth and development retardation, and to analyze its genotype-phenotype correlation. METHODS: A child who had presented at the Affiliated Children's Hospital of Zhengzhou University on July 9, 2019 was selected as the study subject. Chromosomal karyotypes of the child and her parents were determined with routine G-banding analysis. Their genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array). RESULTS: Karyotyping analysis combined with SNP array suggested that the chromosomal karyotype of the child was 46,XX,dup(7)(q34q36.3), whilst no karyotypic abnormality was found in either of her parents. SNP array has identified a de novo 20.6 Mb duplication at 7q34q36.3 [arr[hg19] 7q34q36.3(138335828_158923941)×3] in the child. CONCLUSION The partial trisomy 7q carried by the child was rated as a de novo pathogenic variant. SNP array can clarify the nature and origin of chromosomal aberrations. Analysis of the correlation between genotype and phenotype can facilitate the clinical diagnosis and genetic counseling.
Female ; Humans ; Trisomy/genetics* ; Phenotype ; Genotype ; Karyotyping ; Chromosome Banding

Clinical data and genetic mutation characteristics of a patient with Coffin-Siris syndrome by 6q25.3 deletion were summarized. The child was a 7-year and 6-month old girl who had feeding difficulties, repeated infection, language and motor retardation, low intelligence, laryngeal cartilage dysplasia, thick eyebrows, sparse teeth, hairy back, hyperactivity and aggressive behavior, seizures and ataxia. There was no abnormality in chromosomal karyotype analysis by proband; genomic copy number variant sequencing (CNV-seq) indicated approximately 4.27 Mb heterozygous deletion in chromosome 6q25.3 region, with 17 genes including ARID1B gene, father maternal CNV-seq showing no abnormalities. Trio-whole-exome sequencing showed the proband missed all exons 1-20 of the ARID1B gene, with wild-type parents. The proband had severe clinical symptoms and haplodose insufficiency which was the genetic etiology.

OBJECTIVE: To explore the genetic basis of a pedigree affected with peroneal muscular atrophy. METHODS: Neuroelectrophysiological examination and whole exome sequencing were carried out for the proband, a six-year-and-ten-month-old boy. Suspected variant was verified in his family members through Sanger sequencing. Bioinformatic analysis was carried to predict the conservation of amino acid sequence and impact of the variant on the protein structure and function. RESULTS: Electrophysiological examination showed demyelination and axonal changes of motor and sensory nerve fibers. A heterozygous missense c.1066A>G (p. Thr356Ala) variant was found in exon 11 of the MFN2 gene in the proband and his mother, but not in his sister and father. Bioinformatic analysis using PolyPhen-2 and Mutation Taster software predicted the variant to be pathogenic, and that the sequence of variation site was highly conserved among various species. Based no the American College of Medical Genetics and Genomics standards and guidelines, the c.1066A>G (p. Thr356Ala) variant of MFN2 gene was predicted to be likely pathogenic (PS1+ PM2+ PP3+ PP4). CONCLUSION The heterozygous missense c.1066A>G (p.Thr356Ala) variant of the MFN2 gene probably underlay the disease in the proband, and the results have enabled genetic counseling and prenatal diagnosis for this family.
Charcot-Marie-Tooth Disease/genetics* ; Child ; China ; Drosophila Proteins/genetics* ; Exons ; Female ; Heterozygote ; Humans ; Male ; Membrane Proteins/genetics* ; Mutation ; Pedigree ; Pregnancy ; Whole Exome Sequencing

OBJECTIVE: To detect variants of NF1 gene among thirteen patients with neurofibromatosis type 1. METHODS: Genomic DNA was extracted from peripheral blood samples of the patients. High-throughput sequencing was employed to detect potential variants of the NF1 and NF2 genes. RESULTS: Thirteen pathogenic variants were identified among the patients, which included one NF1 deletion, three missense variants, three nonsense variants and six frameshifting variants. Among these, 10 variants have been associated with neurofibromatosis type 1. c.4180A>T (p.Asn1394Tyr), c.4217dupT (p.Leu1406fs) and c.1753dupT(p.Leu585Phefs*3) were unreported previously. Based on the guidelines of the American College of Medical Genetics and Genomics, c.4180A>T (p.Asn1394Tyr) was predicted to be likely pathogenic (PS2+PM1+PM2+PP2), while c.4217dupT (p.Leu1406fs) and c.1753dupT (p.Leu585Phefs*3) were predicted to be pathogenic (PVS1+PS2+PM2). CONCLUSION Variants of the NF1 gene probably underlay the disease among these children. Above findings have enriched the the spectrum of NF1 gene variants.
Child ; Genes, Neurofibromatosis 1 ; Genomics ; High-Throughput Nucleotide Sequencing ; Humans ; Mutation ; Neurofibromatosis 1/genetics*

OBJECTIVE: To delineate the nature and origin of chromosomal aberration in a girl with mental retardation. METHODS: Genomic DNA was analyzed by using single nucleotide polymorphism-based array (SNP array). The proband and her parents were subjected to routine G-banded chromosomal karyotyping analysis. RESULTS: SNP array has identified a 1.2 Mb microdeletion at 10p15.3 and a duplication at 18p11.21-pter in the proband. The patient was also found to harbor a structural aberration involving 10p. The karyotype of her father was 46,XY,t(10;18)(p15;p11.2), while her mother was found to be normal. CONCLUSION The structural aberration of 10p carried by the patient has derived from her father whom has carried a balanced translocation of t(10;18). Her karyotype was finally determined as 46,XX,der(10)t(10;18)(p15;p11.2)pat. The abnormal phenotype of the patient can probably be attributed to the presence of 10p15.3 microdeletion and 18p11.21-pter duplication.

OBJECTIVE: To delineate the nature and origin of chromosomal aberration in a boy with mental retardation and multiple congenital deformities. METHODS: Chromosomal karyotypes of the proband and his parents were determined by routine G-banding analysis. Genomic DNA was also analyzed with single nucleotide polymorphism array (SNP array). RESULTS: The karyotype of the proband was 46,X,add(Y)(q11.23). No karyotypic abnormality was detected in either parent. SNP array has identified a de novo 21.6 Mb duplication at 22q12qter in the proband. CONCLUSION The de novo 22q12qter duplication probably underlies the abnormalities in the proband.
Abnormalities, Multiple ; genetics ; Adult ; Child ; Chromosome Banding ; Chromosomes, Human, Pair 22 ; genetics ; Female ; Genetic Testing ; Humans ; Intellectual Disability ; genetics ; Karyotyping ; Male ; Trisomy

OBJECTIVE: To explore the clinical characteristics and genetic variants in a child with tyrosine hydroxylase-deficient infantile Parkinsonism with motor delay. METHODS: Clinical feature of the patient was summarized. Genomic DNA was extracted from peripheral blood samples taken from the child and her family members. All exons of GCH1, TH and SPR genes were subjected to targeted capture and next-generation sequencing. Suspected variants were verified by Sanger sequencing. RESULTS: The child could not sit alone at 7 month and 11 days. Physical examination suggested motor retardation and hypotonia, limb stiffness, head nodding, slight torticollis, and language and intellectual developmental delays. She developed involuntary shaking of limbs at 3 month old, which lasted approximately 10 seconds and aggregated with excitement and before sleeping. Cranial MRI revealed widening of subarachnoid space on the temporomandibular and particularly temporal sides. Genetic testing revealed that she has carried a nonsense c.457C>T (p.R153X) variant, which was known to be pathogenic, and a novel missense c.720C>G (p.I240M) variant of the TH gene. The two variants were derived from her father and mother, respectively. CONCLUSION The child was diagnosed as tyrosine hydroxylase-deficient infantile Parkinsonism with motor delay due to compound heterozygous variants of the TH gene. Above finding has enriched the spectrum of TH gene variants.
Brain ; diagnostic imaging ; Codon, Nonsense ; Dystonic Disorders ; congenital ; genetics ; Female ; Genetic Testing ; High-Throughput Nucleotide Sequencing ; Humans ; Infant ; Magnetic Resonance Imaging ; Mutation ; Parkinsonian Disorders ; genetics ; Tyrosine 3-Monooxygenase ; genetics