Objective:To summarize the prenatal ultrasound features of fetal cleidocranial dysplasia (CCD) and provide references for clinical consultation.Methods:A retrospective analysis was conducted on the prenatal ultrasound features, genetic testing results, and prognosis of a CCD fetus diagnosed at Qingdao Women and Children's Hospital in June 2023. Relevant literature on CCD was retrieved from the CNKI, Yiigle, Wanfang, and PubMed databases including cases confirmed by genetic testing or postnatal clinical phenotype and imaging with relatively complete prenatal ultrasound information. The prenatal ultrasound features of CCD fetuses were summarized using descriptive statistical analysis.Results:(1) In this case, prenatal ultrasound at 25 weeks of gestation indicated widened cranial sutures with clear near-field intracranial structures, absence of the nasal bone, shortened and rigid bilateral clavicles, and mildly shortened bilateral femurs and humeri. Chromosomal karyotyping and chromosomal microarray analysis showed no abnormalities, but whole exome sequencing detected a RUNX2 gene mutation, leading to a diagnosis of CCD combined with the ultrasound phenotype. At 36 weeks of gestation, the mother experienced premature rupture of membranes and delivered a male infant vaginally. Bedside X-rays indicated bilateral wet lungs and bilateral clavicular dysplasia in the newborn. Telephone follow-up at 9 months showed no abnormalities in growth and development. (2) Literature review: Thirteen cases from 13 articles were included, along with this case, totaling 14 CCD fetuses. The main ultrasound phenotypes of CCD fetuses were clavicular dysplasia (12/14), incomplete cranial ossification (10/14), absence of the nasal bone (8/14), and shortening of the femur (12/14). Other ultrasound phenotypes included scapular dysplasia, short ribs, and increased interocular distance. Conclusion:Clavicular dysplasia and incomplete cranial ossification are the most specific signs of fetal CCD, while absence of the nasal bone and mild femoral shortening are secondary features of CCD.

The development of high-throughput sequencing techniques enabled a deeper and more comprehensive understanding of environmental microbiology. Specifically, the third-generation sequencing techniques represented by nanopore sequencing have greatly promoted the development of environmental microbiology research due to its advantages such as long sequencing reads, fast sequencing speed, real-time monitoring of sequencing data, and convenient machine carrying, as well as no GC bias and no PCR amplification requirement. This review briefly summarized the technical principle and characteristics of nanopore sequencing, followed by discussing the application of nanopore sequencing techniques in the amplicon sequencing, metagenome sequencing and whole genome sequencing of environmental microorganisms. The advantages and challenges of nanopore sequencing in the application of environmental microbiology research were also analyzed.
Environmental Microbiology ; High-Throughput Nucleotide Sequencing ; Metagenome ; Nanopore Sequencing ; Nanopores