OBJECTIVE: To explore the clinical phenotypes and genetic diagnosis of 2 sporadic cases for cleidocranial dysplasia. METHODS: The clinical data of two cases of CCD admitted to the Third Affiliated Hospital of Zhengzhou University on December 16, 2021 and December 9, 2021 were analyzed retrospectively, and the whole exome sequencing (WES), chromosome microarray analysis and copy number variation sequencing were performed. RESULTS: The main ultrasonographic findings of the fetus had included poorly calcified skull bones, budging of parieto-occipital area, compression and deformation of skull, and loss of nasal bone. The infant's clinical phenotypes included delayed closure of anterior fontanelle, recurrent respiratory tract infection, growth retardation, and clavicular hypoplasia. By WES analysis, the fetus was found to harbor a heterozygous c.911_914delinsTTT variant of the RUNX2 gene, whilst the infant was found to harbor a heterozygous c.1008delT variant of the RUNX2 gene. Both variants were verified by Sanger sequencing to have occurred de novo. CONCLUSION For sporadic cases featuring cleidocranial dysplasia, prenatal ultrasonography is particularly important. Hypoplastic clavicle, skull calcification and nasal bone absence are the main features. Diagnosis should also be suspected for infants featuring growth retardation, recurrent respiratory tract infections and clavicular dysplasia. The identification of the c.911_914delinsTTT and c.1008delT variants of the RUNX2 gene has facilitated genetic counseling and prenatal diagnosis, and also expanded the mutational spectrum of the RUNX2 gene.
Female ; Humans ; Pregnancy ; Cleidocranial Dysplasia/genetics* ; Core Binding Factor Alpha 1 Subunit ; DNA Copy Number Variations ; Growth Disorders ; Retrospective Studies

OBJECTIVE: To detect the genetic variant of a child with cleidocranial dysplasia (CCD) and to find out the causation of the illness. METHODS: Gene variant was identified by the second generation targeted sequencing and Sanger sequencing. RESULTS: The gene sequencing revealed that the RUNX2 gene had c.196C>T(p.Glu66*) nonsense variant, which was predicted to be a pathogenic variant according to the ACMG guidelines(PVS1+PS2). CONCLUSION The variant of c.196C > T in the RUNX2 gene may be the cause of the child with CCD, and the novel variant enriches the RUNX2 gene variant spectrum.
Asians/genetics* ; Child ; China ; Cleidocranial Dysplasia/genetics* ; Core Binding Factor Alpha 1 Subunit/genetics* ; Humans ; Mutation

OBJECTIVE: To analyze the clinical features and pathogenic variant in a Chinese pedigree affected with cleidocranial dysplasia (CCD). METHODS: Clinical data of 8 patients from the pedigree was collected, including physical examination and X-ray images of head, face, spine, limbs, and mouth. Peripheral blood samples were collected from 6 affected members for the extraction of genomic DNA. The proband and other 3 patients were subjected to trio-whole exome sequencing. Candidate variant was verified by Sanger sequencing of the other 2 affected members from the pedigree. RESULTS: This pedigree has included 22 members (8 affected) from four generations. Genetic testing revealed that the proband has harbored a novel pathogenic variant of the RUNX2 gene [NM_001024630: c.1268_1277del (p.P425Afs*56)], which was inherited from her mother and carried by all affected members in the pedigree. The same variant was not detected among the unaffected members, suggesting co-segregation with the phenotype. CONCLUSION The c.1268_1277del (p.P425Afs*56) variant of the RUNX2 gene probably underlay the pathogenesis of CCD in this pedigree. Genetic testing has facilitated the definite diagnosis and enabled prenatal diagnosis.
Humans ; Pregnancy ; Female ; Cleidocranial Dysplasia/genetics* ; Pedigree ; Core Binding Factor Alpha 1 Subunit/genetics* ; Phenotype ; China ; Mutation

OBJECTIVE: To explore the genetic basis for a Chinese patient featuring cleidocranial dysplasia(CCD). METHODS: Genomic DNA was extracted from peripheral blood samples of the patient and his parents. Whole exome sequencing (WES) was carried out for the patient, and suspected variant was verified by Sanger sequencing. RESULTS: WES has identified a missense c.460G>T (p.Val154Phe) (GRCh37/hg19) variant of the RUNX2 gene. The variant was located in the Runt domain, a highly conserved region (PM1); it was not present in either the Genome Aggregation Database or the 1000 Genomes Project (PM2), and was predicted to have a deleterious effect on the gene product by multiple in silico prediction tools (PP3); the clinical phenotype of the patient was highly consistent with that of cleidocranial dysplasia (PP4). Furthermore, the variant was unreported in medical literature and was absent in both parents (PS2). Based on the American College of Medical Genetics and Genomics guidelines, the c.460 G>T variant of RUNX2 gene was predicted to be pathogenic (PS2+PM1+PM2+PP3+PP4). CONCLUSION The c.460G>T (p.Val154Phe) variant of the RUNX2 gene probably underlay the clinical phenotype in the patient. Above finding has enabled accurate diagnosis and expanded the spectrum of RUNX2 variants.
China ; Cleidocranial Dysplasia/genetics* ; Core Binding Factor Alpha 1 Subunit/genetics* ; Humans ; Mutation ; Whole Exome Sequencing

OBJECTIVETo carry out genetic analysis on a child with developmental delay and multiple malformation.

METHODSThe karotypes of the child and her parents were analyzed with routine chromosomal G-banding. Their genomic DNA was analyzed with array comparative genomic hybridization (aCGH).

RESULTSThe karyotype of the proband was determined as 46,XX,del(6)(q22),inv(6)(p21.1q21), while no karyotypic abnormality was detected in her parents. aCGH has identified in the child a de novo 800 kb deletion encompassing the RUNX2 gene at 6p21.1 and a de novo 11.79 Mb deletion at 6q21-q22.31.

CONCLUSIONBoth of the de novo deletions are pathogenic. Deletion of the RUNX2 gene probably underlies the cleidocranial dysplasia in the patient, while the 6q21-q22.31 deletion may result in malformation of the brain.

Child, Preschool ; Chromosome Banding ; Chromosome Deletion ; Chromosomes, Human, Pair 6 ; Cleidocranial Dysplasia ; genetics ; Comparative Genomic Hybridization ; Core Binding Factor Alpha 1 Subunit ; genetics ; Female ; Genetic Testing ; Humans ; Karyotyping

BACKGROUNDCleidocranial dysplasia (CCD) is an autosomal dominant disease that affects the skeletal system. Common symptoms of CCD include hypoplasia or aplasia of the clavicles, delayed or even absent closure of the fontanels, midface hypoplasia, short stature, and delayed eruption of permanent and supernumerary teeth. Previous studies reported a connection between CCD and the haploinsufficiency of runt-related transcription factor 2 (RUNX2). Here, we report a sporadic Chinese case presenting typical symptoms of CCD.

METHODSWe made genetic testing on this sporadic Chinese case and identified a novel RUNX2 frameshift mutation: c.1111dupT. In situ immunofluorescence microscopy and osteocalcin promoter luciferase assay were performed to compare the functions of the RUNX2 mutation with those of wild-type RUNX2.

RESULTSRUNX2 mutation was observed in the perinuclear region, cytoplasm, and nuclei. In contrast, wild-type RUNX2 was confined in the nuclei, which indicated that the subcellular compartmentalization of RUNX2 mutation was partially perturbed. The transactivation function on osteocalcin promoter of the RUNX2 mutation was obviously abrogated.

CONCLUSIONSWe identified a sporadic CCD patient carrying a novel insertion/frameshift mutation of RUNX2. This finding expanded our understanding of CCD-related phenotypes.

Adolescent ; Cell Nucleus ; metabolism ; Cleidocranial Dysplasia ; genetics ; Core Binding Factor Alpha 1 Subunit ; genetics ; Female ; Frameshift Mutation ; genetics ; Humans ; Microscopy, Fluorescence ; Mutation

Cleidocranial dysplasia is a well-documented rare autosomal dominant skeletal dysplasia characterized by hypoplastic/aplastic clavicles, brachycephalic skull, patent sutures and fontanelles, midface hypoplasia, and abnormalities of dentition. Patients with cleidocranial dysplasia often complain about undesirable esthetic appearance of their forehead and skull. Notwithstanding many studies of molecular, genetics and skeletal abnormalities of this congenial disorder, there have been very few written reports of cranioplasty involving cleidocranial dysplasia. Thus, we report a rare case of successful cranioplasty using a modified split calvarial graft technique in patient with cleidocranial dysplasia.
Clavicle ; Cleidocranial Dysplasia* ; Dentition ; Forehead ; Genetics ; Humans ; Skull ; Sutures ; Transplants*

OBJECTIVETo investigate the molecular etiology of three patients with sporadic cleidocranial dysplasia (CCD) and to provide genetic counseling and prenatal diagnosis for the family members based on the identified mutations.

METHODSGenomic DNA was extracted from peripheral blood samples using a standard method. All 7 coding exons of the RUNX2 gene and their flanking intronic sequences were amplified by PCR and sequenced directly. The PCR products of the exons with mutations from the three patients were cloned into a T-vector. Positive clones were sequenced.

RESULTSThe three patients who have the typical CCD phenotypes involving clavicles, calvarium, stature, and teeth have carried various frameshift mutations in the RUNX2 gene. Patient 1 has a gross deletion of 80 nucleotides in exon 1 (c.227_306del), which caused a frameshift beginning at the Q/A repeat of the polypeptide and a premature termination (p.Ala76GlyfsX58). Patient 2 has a 2-bp duplication in exon 2 (c.471_472dupGG), which also caused a frameshift and a premature termination (p.Ala158GlyfsX19). Patient 3 has a T duplication in exon 7 (c.1321dupT), which caused a frameshift and a premature termination (p.Ser370PhefsX13) as well.

CONCLUSIONThe three novel mutations in RUNX2 are the underlying molecular mechanism for the CCD phenotypes of three sporadic Chinese patients, respectively. These have broadened the mutation spectrum of RUNX2 gene and provided a molecular basis for the genetic counseling and prenatal diagnosis for the affected families.

Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Base Sequence ; Child ; Cleidocranial Dysplasia ; genetics ; Core Binding Factor Alpha 1 Subunit ; genetics ; Exons ; Female ; Frameshift Mutation ; Humans ; Introns ; Male ; Molecular Sequence Data

Adult ; Cleidocranial Dysplasia ; genetics ; pathology ; Female ; Humans ; Male ; Middle Aged

OBJECTIVETo analyze the mutations of the RUNX2 gene in a family with cleidocranial dysplasia (CCD).

METHODSThe general health status of family members with CCD was investigated through propositus verification method. Oral specialized examination and radiological examination were performed. The peripheral venous blood of the proband and her parents and sisters was collected. Genomic DNA was extracted, and the RUNX2 gene from this DNA was amplified by polymerase chain reaction (PCR). DNA sequences were analyzed with the Blastn program.

RESULTSAfter Blastn analysis, heterozygous C to T transition mutation at nucleotide 568 occurred in exon 2, which converted arginine to tryptophane at codon 190 (c.568C>T, CGG-->TGG).

CONCLUSIONRUNX2 gene is responsible for the CCD in the Chinese family under study. The c.568C>T mutation is the molecular basis of the CCD in the family.

Asian Continental Ancestry Group ; Base Sequence ; Cleidocranial Dysplasia ; genetics ; Core Binding Factor Alpha 1 Subunit ; genetics ; DNA Mutational Analysis ; Exons ; Humans ; Mutation ; Pedigree ; Polymerase Chain Reaction