OBJECTIVE: To investigate the prenatal manifestation and genetic basis for two fetuses suspected for Osteocraniostenosis (OCS). METHODS: Two fetuses undergoing invasive prenatal diagnosis at Cangzhou People's Hospital in April and August 2021 for short long bones and abnormal skull morphology were selected as the study subjects. Clinical data were collected and analyzed. Genomic DNA was extracted from amniotic fluid and peripheral blood samples of the two couples. Candidate variants were validated by Sanger sequencing. Literature was retrieved from CNKI, Wanfang Data Knowledge Service Platform and PubMed using keywords including "FAM111A gene", "gracile bone dysplasia", "FAM111A" and "osteocraniostenosis" from January 1, 2000 to June 30, 2025. This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: K2020-049). RESULTS: Fetus 1 was found to have short limbs, abnormal skull morphology and shallow cerebral sulci. Fetus 2 showed short limbs, irregular skull halo, prominent forehead and bilateral frontal narrowing. Trio-WES revealed that fetus 1 has carried a heterozygous missense variant c.1582G>C (p.Asp528His) in exon 4 of the FAM111A gene, which was unreported previously. Fetus 2 has harbored a heterozygous in-frame deletion c.1020_1022delTTC (p.Ser343del) in exon 6 of the FAM111A gene, which has been recorded as likely pathogenic by the ClinVar and HGMD databases. Sanger sequencing confirmed that the parents of both fetuses were wild-type for the variant sites. A total of 9 previously reported patients with FAM111A-related gracile bone dysplasia/OCS from 4 publications were retrieved. The main clinical features included intrauterine growth restriction, hypomineralized skull, gracile long bones with narrow medullary cavities and characteristic facial anomalies, which were in large in keeping with the prenatal features of the two fetuses. CONCLUSION Both fetuses were diagnosed with FAM111A-related OCS based on the characteristic prenatal findings and identification of the FAM111A variants. Above finding expanded the phenotypic spectrum of FAM111A-associated disorders and provided clues for the prenatal diagnosis and genetic counseling.
Humans ; Female ; Pregnancy ; Prenatal Diagnosis ; Phenotype ; Fetus ; Male ; Bone Diseases, Developmental/genetics* ; Adult

OBJECTIVE: To explore the genetic etiology of fetal skeletal dysplasia using whole exome sequencing (WES) and copy number variation sequencing (CNV-seq) techniques, and the feasibility of using WES as the first-tier method for such fetuses. METHODS: Seventy four fetuses with skeletal dysplasia detected by prenatal ultrasound at the Genetic Testing Center of the Women and Children's Hospital Affiliated to Qingdao University from January 2020 to August 2024 were selected as the study subjects. Fetal muscle and peripheral blood samples of the pregnant women and their spouses were collected and subjected to WES analysis. CNV-seq was carried out on all fetal muscle tissue samples. And the results were compared with the CNVs indicated by WES. Genetic etiologies were analyzed across different subtypes of skeletal dysplasia. And the feasibility of using WES as the first-tier genetic test for similar fetuses was assessed, in addition with a systematic cost-effectiveness analysis. This study was approved by the Medical Ethics Committee of the Hospital (Ethics No.: QFELL-YJ-2024-201). RESULTS: A total of 50 fetuses were diagnosed, which yielded a diagnostic rate of 67.57%. These included 6 chromosomal aneuploidies, 4 chromosomal CNVs and 40 monogenic disorders. The monogenic diseases had involved 46 variant sites in 23 pathogenic genes, among which 12 were unreported previously, including MYH3: c.735T>C, ALPL: c.1324C>T, NEK9: c.1973G>A, MAGEL2: c.2024_2025del, LMBR1: c.423+4914A>C, NEB: c.21273_21276del, COL1A1: c.2651G>C and c.2758G>C, ASPM: c.2473delinsGA, TBX5: c.704G>A, DYNC2H1: c.10893del, and DYNC2I2: c.1270C>T. Substantial concordance was reached between WES-derived CNV calls and CNV-seq findings. No clinically significant CNV was exclusively detected by CNV-seq. Cost-effectiveness modeling demonstrated that implementing WES as the first-tier genetic testing method could reduce the total expenditure when WES unit cost remained below 6.4 folds that of the CNV-seq. CONCLUSION Genetic variants including single nucleotide variations (SNV) of monogenic disorders, chromosomal aneuploidies and genomic CNVs are important causes for fetal skeletal dysplasia. WES is an accurate and efficient method for analyzing the etiology of fetal skeletal dysplasia, particularly in those with a family history of similar phenotype or maternal history of adverse pregnancies.
Humans ; Exome Sequencing/methods* ; Female ; Pregnancy ; DNA Copy Number Variations/genetics* ; Genetic Testing/methods* ; Prenatal Diagnosis/methods* ; Adult ; Male ; Fetus ; Bone Diseases, Developmental/diagnosis* ; Ultrasonography, Prenatal

OBJECTIVE: To explore the clinical and genetic characteristics of three children with KBG syndrome. METHODS: Clinical data of the three children from two families who have presented at the First Affiliated Hospital of Zhengzhou University between October 2019 and September 2020 and their family members were collected. Trio-whole exome sequencing (trio-WES) and Sanger sequencing were carried out. RESULTS: All children had feeding difficulties, congenital heart defects and facial dysmorphism. The sib- pair from family 1 was found to harbor a novel de novo heterozygous c.6270delT (p.Q2091Rfs*84) variant of the ANKRD11 gene, whilst the child from family 2 was found to harbor a novel heterozygous c.6858delC (p.D2286Efs*51) variant of the ANKRD11 gene, which was inherited from his mother who had a mild clinical phenotype. CONCLUSION The heterozygous frameshift variants of the ANKRD11 gene probably underlay the disease in the three children. Above findings have enriched the spectrum of the ANKRD11 gene variants.
Female ; Child ; Humans ; Abnormalities, Multiple/genetics* ; Intellectual Disability/genetics* ; Bone Diseases, Developmental/genetics* ; Tooth Abnormalities/genetics* ; Facies ; Repressor Proteins/genetics* ; Mothers ; Mutation

Humans ; Adamantinoma/surgery* ; Bone Diseases, Developmental ; Bone Neoplasms/surgery* ; Tibia/surgery*

Objective: To analyze the clinical and genetic characteristics of pediatric patients with dual genetic diagnoses (DGD). Methods: Clinical and genetic data of pediatric patients with DGD from January 2021 to February 2022 in Peking University First Hospital were collected and analyzed retrospectively. Results: Among the 9 children, 6 were boys and 3 were girls. The age of last visit or follow-up was 5.0 (2.7,6.8) years. The main clinical manifestations included motor retardation, mental retardation, multiple malformations, and skeletal deformity. Cases 1-4 were all all boys, showed myopathic gait, poor running and jumping, and significantly increased level of serum creatine kinase. Disease-causing variations in Duchenne muscular dystrophy (DMD) gene were confirmed by genetic testing. The 4 children were diagnosed with DMD or Becker muscular dystrophy combined with a second genetic disease, including hypertrophic osteoarthropathy, spinal muscular atrophy, fragile X syndrome, and cerebral cavernous malformations type 3, respectively. Cases 5-9 were clinically and genetically diagnosed as COL9A1 gene-related multiple epiphyseal dysplasia type 6 combined with NF1 gene-related neurofibromatosis type 1, COL6A3 gene-related Bethlem myopathy with WNT1 gene-related osteogenesis imperfecta type XV, Turner syndrome (45, X0/46, XX chimera) with TH gene-related Segawa syndrome, Chromosome 22q11.2 microduplication syndrome with DYNC1H1 gene-related autosomal dominant lower extremity-predominant spinal muscular atrophy-1, and ANKRD11 gene-related KBG syndrome combined with IRF2BPL gene-related neurodevelopmental disorder with regression, abnormal movement, language loss and epilepsy. DMD was the most common, and there were 6 autosomal dominant diseases caused by de novo heterozygous pathogenic variations. Conclusions: Pediatric patients with coexistence of double genetic diagnoses show complex phenotypes. When the clinical manifestations and progression are not fully consistent with the diagnosed rare genetic disease, a second rare genetic disease should be considered, and autosomal dominant diseases caused by de novo heterozygous pathogenic variation should be paid attention to. Trio-based whole-exome sequencing combining a variety of molecular genetic tests would be helpful for precise diagnosis.
Humans ; Abnormalities, Multiple ; Retrospective Studies ; Intellectual Disability/genetics* ; Bone Diseases, Developmental/complications* ; Tooth Abnormalities/complications* ; Facies ; Muscular Dystrophy, Duchenne/complications* ; Muscular Atrophy, Spinal/complications* ; Carrier Proteins ; Nuclear Proteins

OBJECTIVE: To assess the diagnostic value of copy number variation sequencing (CNV-seq) in the genetic etiology of fetuses with nasal bone dysplasia (NBD). METHODS: A total of 217 fetuses discovered with NBD from December 2017 to December 2020 were divided into the isolated NBD group and NBD combined with other anomalies group, for which copy number variations (CNVs) were analyzed. RESULTS: A total of 40 fetal abnormalities were detected in 217 cases, with an overall abnormal rate of 18.4%. These included 31 cases with aneuploidies (14.3%, 31/217) and 9 cases with genomic CNVs (4.1%, 9/217). Five cases of trisomy 21 (3.5%, 5/144) and two CNVs cases with unknown clinical significance (1.4%, 2/144) were detected in the isolated group. As for the combined NBD group, 26 aneuploidies (35.6%, 26/73), including 19 cases with trisomy 21, 6 cases with trisomy 18, 1 case with trisomy 13, 5 cases with pathogenic CNVs (6.8%, 5/73), and 2 cases with CNVs of unknown clinical significance (2.7%, 2/73) were detected. A significant difference was detected between the two groups (P < 0.01). CONCLUSION The detection rate of CNV-seq is high for chromosomal aneuploidies and pathogenic CNVs in fetuses with NBD, particularly in those combined with other ultrasonic abnormalities.
Aneuploidy ; Bone Diseases, Developmental ; Chromosome Aberrations ; DNA Copy Number Variations ; Down Syndrome/genetics* ; Female ; Fetus/abnormalities* ; Humans ; Pregnancy ; Prenatal Diagnosis ; Trisomy

OBJECTIVE: To summarize the clinical phenotype and genotypic characteristics of 3 patients with KBG syndrome and epileptic seizure. METHODS: Clinical data of the patients were collected. Family-trio whole exon sequencing (WES) was carried out. Candidate variants were verified by Sanger sequencing. RESULTS: Patients 1 and 2 were boys, and patient 3 was an adult woman. All patients had epileptic seizures and mental deficiency. Their facial features included triangular face, low hair line, hypertelorism, large forward leaning auricles, broad nasal bridge, upturned nostrils, long philtrum, arched upper lip, and macrodontia. The two boys also had bilateral Simian creases. WES revealed that the three patients all harbored heterozygous de novo frameshift variants in exon 9 of the ANKRD11 gene including c.2948delG (p.Ser983Metfs*335), c.5397_c.5398insC (p.Glu1800Argfs*150) and c.1180_c.1184delAATAA (p.Asn394Hisfs*42). So far 291 patients with ANKRD11 gene variants or 16q24.3 microdeletions were reported, with over 75% being de novo mutations. CONCLUSION Above findings have enriched the spectrum of ANKRD11 gene mutations underlying KBG syndrome. WES is helpful for the early diagnosis of KBG, and provided reference for genetic counseling of this disease.
Abnormalities, Multiple/genetics* ; Bone Diseases, Developmental/genetics* ; Epilepsy/genetics* ; Facies ; Humans ; Intellectual Disability/genetics* ; Phenotype ; Repressor Proteins/genetics* ; Seizures/genetics* ; Tooth Abnormalities/genetics*

OBJECTIVE: To explore gender difference in the clinical manifestations of two children with Keishi-Bukuryo-Gan syndrome (KBGS). METHODS: Clinical manifestations of the two children were reviewed. Genetic testing was carried out through next generation sequencing (NGS). Treatment was summarized, and the prognosis was followed up. RESULTS: Both children showed particular appearance including megatooth, abnormal hair distribution, hands' abnormality and language development delay. NGS revealed that both children have carried pathogenic variants of the ANKRD11 gene (c.1903_1907del and c.4911delT), which resulted in shifting of amino acid sequences starting from the Lysine and Proline at positions 635 and 1638, respectively. The female patient exhibited central precocious puberty. Her height has increased by 13 cm, and sex characteristics has retracted after treatment with leuprorelin for 23 months and recombinant human growth hormone for 1 month. CONCLUSION Comparison of the two cases with different genders and summary of previously reported cases found that male KBGS patients have more obvious dysmorphisms such as triangular face, synophrys, ocular hypertelorism and vertebral body abnormality, with higher morbidity of epilepsy, mental retardation, autism, congenital heart disease, immune thrombocytopenia and other complications. KBGS is an autosomal dominant disease featuring more evident peculiar appearance and global development delay. Male patients often have multi-system involvement, and multidisciplinary cooperation is required for early recognition of particular features in order to improve the prognosis.
Abnormalities, Multiple ; Bone Diseases, Developmental ; Child ; Facies ; Female ; Humans ; Intellectual Disability ; Male ; Phenotype ; Repressor Proteins/genetics* ; Sex Characteristics ; Tooth Abnormalities

OBJECTIVE: To explore strategies of prenatal genetic testing for fetuses featuring abnormal skeletal development. METHODS: Clinical data of 17 fetuses with skeletal dysplasia was collected. The results of genetic testing and outcome of pregnancy were analyzed. RESULTS: For 12 fetuses, the femur-to-foot length ratio was less than 0.9. Thirteen fetuses had a positive finding by genetic testing. One fetus was diagnosed with chromosomal aneuploidy, three were diagnosed with microdeletion/microduplications, and nine were diagnosed with hereditary bone diseases due to pathological variants of FGFR3, COL1A2, GPX4 or ALPL genes. CONCLUSION For fetuses with skeletal dysplasia characterized by short femur, in addition to chromosomal karyotyping and microarray analysis, sequencing of FGFR3 and other bone disease-related genes can improve the diagnostic rate.
Bone Diseases, Developmental/genetics* ; Female ; Fetus/diagnostic imaging* ; Genetic Testing ; Humans ; Karyotyping ; Pregnancy ; Prenatal Diagnosis ; Receptor, Fibroblast Growth Factor, Type 3/genetics* ; Ultrasonography, Prenatal

The Hedgehog (Hh) signalling pathway is essential for cellular proliferation and differentiation during embryonic development. Gain and loss of function of Hh signalling are known to result in an array of craniofacial malformations. To determine the critical period for Hh pathway antagonist-induced frontal bone hypoplasia, we examined patterns of dysmorphology caused by Hh signalling inhibition. Pregnant mice received a single oral administration of Hh signalling inhibitor GDC-0449 at 100 mg•kg or 150 mg•kg body weight at preselected time points between embryonic days (E)8.5 and 12.5. The optimal teratogenic concentration of GDC-0449 was determined to be 150 mg•kg. Exposure between E9.5 and E10.5 induced frontal bone dysplasia, micrognathia and limb defects, with administration at E10.5 producing the most pronounced effects. This model showed decreased ossification of the frontal bone with downregulation of Hh signalling. The osteoid thickness of the frontal bone was significantly reduced. The amount of neural crest-derived frontal bone primordium was reduced after GDC-0449 exposure owing to a decreased rate of cell proliferation and increased cell death.
Administration, Oral ; Anilides ; pharmacology ; Animals ; Bone Diseases, Developmental ; chemically induced ; Cell Proliferation ; drug effects ; physiology ; Female ; Frontal Bone ; abnormalities ; Hedgehog Proteins ; antagonists & inhibitors ; Limb Deformities, Congenital ; chemically induced ; Mice ; Micrognathism ; chemically induced ; Osteogenesis ; drug effects ; Pregnancy ; Pyridines ; pharmacology ; Signal Transduction ; drug effects