ABSTRACT
Objective:To evaluate the clinical value of prenatal molecular diagnostic technology in preventing hereditary diseases through analysis of prenatal diagnostic characteristics in 22 monogenic skeletal disorders pedigrees.Methods:This study retrospectively analyzed prenatal molecular diagnostic results of 22 pedigrees with monogenic skeletal disorders who were admitted to Department of Osteoporosis and Bone Diseases in our hospital from January 2014 to July 2021.Results:Among 22 pedigrees, there were 10 pedigrees with X-linked hypophosphatemic rickets due to PHEX gene mutations, in which 8 fetuses were found to carry pathogenic variants; 6 pedigrees with osteopetrosis, including 3 cases of CLCN7 gene mutation, 2 TCIRG1 gene mutation, and 1 CTSK gene mutation, were detected to have 2 affected fetuses and 1 carrier. There were 4 cases of osteogenesis imperfecta, including 2 cases of COL1A1 gene mutation, 1 case of COL1A2 gene mutation, and 1 case of SERPINF1 gene mutation, in which 1 affected fetus and 1 carrier were found; only one case of osteoarthritis with mild chondrodysplasia caused by COL2A1 gene mutation was found to harbor pathogenic variant in fetus; 1 case of hypophosphatasia due to ALPL gene mutation was not detected to carry pathogenic variant in fetus. By the time of follow-up, all 12 affected fetuses were terminated, and the remaining 10 fetuses except for one case still in pregnancy were born in good condition.Conclusion:Prenatal molecular diagnosis may confirm whether the fetus carries pathogenic variants at the first and second trimesters. For monogenic skeletal disorders that comply with Mendel′s law of separation, prenatal diagnosis can be determined by calculating the probability of recurrence of offspring. In addition, for families with de novo mutations in the offspring, it is necessary to pay attention to whether there are mosaic mutations in the parents.