Humans ; East Asian People ; Genetic Profile ; Mutation ; Osteochondrodysplasias/genetics*

OBJECTIVE: To explore the clinical and genetic characteristics of a fetus with Melnick-Needles syndrome (MNS). METHODS: A fetus with MNS diagnosed at Ningbo Women and Children's Hospital in November 2020 was selected as the study subject. Clinical data was collected. Pathogenic variant was screened by using trio-whole exome sequencing (trio-WES). Candidate variant was verified by Sanger sequencing. RESULTS: Prenatal ultrasonography of the fetus had shown multiple anomalies including intrauterine growth retardation, bilateral femur curvature, omphalocele, single umbilical artery, and oligohydramnios. Trio-WES revealed that the fetus has harbored hemizygous c.3562G>A (p.A1188T) missense variant of the FLNA gene. Sanger sequencing confirmed that the variant was maternally derived, whilst its father was of a wild type. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was predicted to be likely pathogenic (PS4+PM2_Supporting+PP3+PP4). CONCLUSION The hemizygous c.3562G>A (p.A1188T) variant of the FLNA gene probably underlay the structural abnormalities in this fetus. Genetic testing can facilitate accurate diagnosis of MNS and provide a basis for genetic counseling for this family.
Child ; Female ; Humans ; Pregnancy ; Abnormalities, Multiple/genetics* ; Fetal Growth Retardation ; Fetus ; Filamins/genetics* ; Genetic Counseling ; Mutation ; Osteochondrodysplasias

OBJECTIVE: To explore the genetic basis of a Chinese pedigree affected with Dyggve-Melchior-Clausen syndrome. METHODS: Whole exome sequencing and Sanger sequencing were carried out to detect potential pathogenic variants associated with the syndrome. The function of candidate variant was verified by Western blotting. RESULTS: A novel homozygous variant, c.1222delG of the DYM gene was detected in the two affected siblings, for which both parents were heterozygous carriers. The variant has caused replacement of Asp by Met at amino acid 408 and generate a premature stop codon p.Asp408Metfs*10. Western blotting confirmed that the variant can result in degradation of the mutant DYM protein, suggesting that it is a loss of function variant. CONCLUSION The homozygous c.1222delG frameshift variant of the DYM probably underlay the Dyggve-Melchior-Clausen syndrome in the two affected siblings. Above findings has enabled clinical diagnosis and genetic counseling for the family.
China ; Dwarfism/genetics* ; Humans ; Intellectual Disability ; Osteochondrodysplasias/genetics* ; Pedigree

OBJECTIVES: To study the clinical features and fibroblast growth factor receptor 3 (FGFR3) gene mutations of children with achondroplasia (ACH) through an analysis of 17 cases. METHODS: A retrospective analysis was performed on the clinical data and FGFR3 gene detection results of 17 children with ACH who were diagnosed from January 2009 to October 2021. RESULTS: Of the 17 children with ACH, common clinical manifestations included disproportionate short stature (100%, 17/17), macrocephaly (100%, 17/17), trident hand (82%, 14/17), and genu varum (88%, 15/17). The common imaging findings were rhizomelic shortening of the long bones (100%, 17/17) and narrowing of the lumbar intervertebral space (88%, 15/17). Major complications included skeletal dysplasia (100%, 17/17), middle ear dysfunction (82%, 14/17), motor/language developmental delay (88%, 15/17), chronic pain (59%, 10/17), sleep apnea (53%, 9/17), obesity (41%, 7/17), foramen magnum stenosis (35%, 6/17), and hydrocephalus (24%, 4/17). All 17 children (100%) had FGFR3 mutations, among whom 13 had c.1138G>A hotspot mutations of the FGFR3 gene, 2 had c.1138G>C mutations of the FGFR3 gene, and 2 had unreported mutations, with c.1252C>T mutations of the FGFR3 gene in one child and c.445+2_445+5delTAGG mutations of the FGFR3 gene in the other child. CONCLUSIONS This study identifies the unreported mutation sites of the FGFR3 gene, which extends the gene mutation spectrum of ACH. ACH is a progressive disease requiring lifelong management through multidisciplinary collaboration.
Achondroplasia/genetics* ; Child ; Humans ; Mutation ; Osteochondrodysplasias/genetics* ; Receptor, Fibroblast Growth Factor, Type 3/genetics* ; Retrospective Studies

OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with microphthalmia. METHODS: Clinical data of the proband was collected. Whole exome sequencing (WES) was carried out to screen potential pathogenic variants in the proband. Candidate variant was verified by Sanger sequencing of the proband and his family members. Pathogenicity of the variant was predicted by searching the PubMed database and bioinformatic analysis. Sanger sequencing of amniotic fluid sample was carried out for prenatal diagnosis. RESULTS: The proband and his father were found to harbor a heterozygous c.151C>G (p.R51G) variant of the MAB21L2 gene. The same variant was not found in his mother and grandparents. Based on the guidelines of American College of Medical Genetics, the c.151C>G (p.R51G) variant was predicted as likely pathogenic. CONCLUSION The c.151C>G (p.R51G) variant of the MAB21L2 gene probably underlay the microphthalmia in the proband. Above finding has facilitated prenatal diagnosis for this pedigree.
China ; Coloboma ; Eye Proteins ; Female ; Humans ; Intracellular Signaling Peptides and Proteins ; Microphthalmos/genetics* ; Mutation ; Osteochondrodysplasias ; Pedigree ; Pregnancy ; Prenatal Diagnosis

OBJECTIVE: To explore the clinical and genetic characteristics of a child with frontometaphyseal dysplasia 1 (FMD1) due to variant of FLNA gene. METHODS: Clinical phenotype of the patient was analyzed. Whole exome sequencing (WES) was carried out to detect pathogenic genetic variants. Sanger sequencing was used to verify the result in his parents. RESULTS: The 2-year-and-9-month-old boy presented with facial dysmorphism (supraorbital hyperostosis, down-slanting palpebral fissure and ocular hypertelorism), skeletal deformities (bowed lower limbs, right genu valgum, left genu varus, slight deformity of index and middle fingers, and flexion contracture of little fingers). He also had limited left elbow movement. High-throughput sequencing revealed that he has carried a de novo heterogeneous c.3527G>A (p.Gly1176Glu) missense variant of the FLNA gene. The same variant was found in neither parent. CONCLUSION The clinical manifestations of FMD1 such as joint contracture and bone dysplasia can occur in infancy and deteriorate with age, and require long-term follow-up and treatment. Above finding has expanded the spectrum of FLNA gene variants.
Child ; Filamins/genetics* ; Forehead/abnormalities* ; Humans ; Infant ; Male ; Osteochondrodysplasias/genetics* ; Phenotype ; Whole Exome Sequencing

Cochlear Implantation ; Cochlear Implants ; Forehead/abnormalities* ; Humans ; Mutation ; Osteochondrodysplasias/genetics*

OBJECTIVE: To explore the molecular basis for a pedigree affected with spondyloepiphyseal dysplasia congenita (SEDC). METHODS: The proband was subjected to whole exome sequencing. Suspected variant was verified by Sanger sequencing. RESULTS: All patients from the pedigree were found to carry a novel missense variant c.1394G>C (p.Gly465Ala) of the COL2A1 gene. The variant was not reported previously. Provean, Polyphen-2 and Mutation Taster software predicted that the variant is highly likely to be pathogenic. CONCLUSION The c.1394G>C (p.Gly465Ala) variant of the COL2A1 gene probably underlies the SEDC in this pedigree.
Asian Continental Ancestry Group ; Collagen Type II ; genetics ; Humans ; Osteochondrodysplasias ; congenital ; genetics ; Pedigree

Adult ; Asian Continental Ancestry Group ; Collagen Type II ; genetics ; Exome ; genetics ; Female ; Genetic Predisposition to Disease ; genetics ; Humans ; Male ; Osteochondrodysplasias ; diagnosis ; genetics ; Pedigree ; Sequence Analysis, DNA

OBJECTIVETo investigate the clinical and genetic features of a Chinese girl with Schwartz-Jampel syndrome (SJS).

METHODTo analyze the clinical and genetic data of a girl with Schwartz-Jampel syndrome who was sent to neurology outpatient department of Beijing Children's Hospital in Auguest of 2010. Reports on Schwartz-Jampel syndrome published until July of 2015 were searched and the clinical and genetic characteristics of reported cases were summarized.

RESULTAt 8 months after birth, the girl showed myotonia; at 1 year old when she was walking alone she had myotonia of lower limbs, both feet evaginated, walked slowly and was prone to fall. At 2 years of age, she could not climb up stairs, at 3 years she could not jump continuously. At 3 years and 7 months of age when the girl was taken to neurology outpatient department, on examination, she had a dull facial expression, rigid lips and could not fully open her mouth, a micromandible, low-set and prominent ears, systemic muscle rigidity, there were muscular nodes formation on the limbs and gait stiffness. She had high level of creatine kinase and atlanto-axial joint subluxation on cervical CT reconstruction. She also had spontaneous myotonia-like discharges on needle electromyography (NEMG). X-ray of limbs showed metaphyseal dysplasia. The patient was treated with neurologic rehabilitation and carbamazepine. The myotonia at the last follow-up at her 8 years of age was the same as at the onset. On her HSPG2 gene, two novel heterozygous mutations c.10776delT on exon 78 and c.5702-5G>A on intron 45 were found. c.10776delT resulted in the amino acid change on p.Ala3592fsX6 and c.5702-5G>A maybe changed protein splicing. No reports were found among Chinese journals, while 7 reports were found in English literature. The total 34 mutations were known in reviewed reports, which included eleven deletion or insertion, twelve splice site, eight missense, and three nonsense mutations. Four patients had a single mutation. No definite genotype-phenotype correlation was identified.

CONCLUSIONSchwartz-Jampel syndrome is a rare autosomal-recessive hereditary disease appears to be slowly progressive, in which distinctive clinical features were induced by HSPG2 gene mutation. We reported the c.10776delT on exon 78 and c.5702-5G>A on intron 45 which were not reported previously. This is the first report of Schwartz-Jampel syndrome of which genetic mutations was identified in a Chinese child.

Asian Continental Ancestry Group ; Carbamazepine ; therapeutic use ; Child ; Child, Preschool ; Exons ; Female ; Heterozygote ; Humans ; Infant ; Introns ; Mutation ; Osteochondrodysplasias ; diagnosis ; genetics