After more than ten years of development, retinal organoid (RO) based on pluripotent stem cells can highly simulate the development process of human retina, provide insight into the mechanism of retinal development and provide new treatments for retinal diseases.At present, RO has been widely used in the research of the mechanism and treatment of retinal diseases, especially in retinitis pigmentosa (RP).This review summarizes the methods of preparing RO from human pluripotent stem cells, and elaborates the mechanism and therapeutic application of RO-RP disease model in different mutated genes such as PRPF31, RPGR, CRB1, RP2, IMPG2, NR2E3, USH2A, PDE6B and TRNT1, as well as the research progress of RO in drug screening, drug toxicity testing, gene therapy and cell therapy, and discusses the research and application challenges of RO.

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.