Prenatal phenotypic analysis and genetic counseling for 22q11.21 microdeletion and microduplication syndrome / 中华围产医学杂志

ABSTRACT

Objective:To analyze the prenatal clinical phenotypes and pregnancy outcomes of fetuses with 22q11.21 microdeletion and microduplication syndrome to provide a basis for clinical genetic counseling.Methods:This retrospective study involved the cases diagnosed with 22q11.21 microdeletion or microduplication by chromosomal microarray analysis (CMA) due to abnormal ultrasound findings, advanced maternal age, or high-risk pregnancies indicated by serum screening in the Prenatal Diagnosis Center of the First Affiliated Hospital of Air Force Medical University from January 2015 to January 2022. Clinical phenotypes and pregnancy outcomes of the fetuses were analyzed and described.Results:Among 9 141 cases referred for CMA during the study period, 77 cases (0.8%) were diagnosed as 22q11.21 microdeletion or microduplication, including 62 (80.5%) with 22q11.21 microdeletion and 15 (19.5%) with microduplication. In the 22q11.21 microdeletion cases, 58 had typical deletion, and four had atypical deletions, but all fetuses carried TBX1 gene that was clearly associated with congenital heart disease. The 15 fetuses with 22q11.21 microduplication including 14 in the typical region and one in the atypical region. Forty-eight (77.4%) out of the 62 fetuses with 22q11.21 microdeletion were complicated by congenital heart defects, including 28 with conotruncal defects. Five of the 15 fetuses with 22q11.21 microduplication were complicated by congenital heart defects. The cases were followed up on telephone at three to six months after the expected date of delivery. Among the 62 cases with 22q11.21 microdeletion, 52 terminated pregnancies, five were lost to follow-up, and five were delivered (one died after one month of premature delivery, one was born with anal advancement and growth retardation, and three were followed up without obvious abnormality). Among the 15 cases with 22q11.21 microduplication, four terminated pregnancies, two were lost to follow-up, and nine gave birth (eight were followed up without obvious abnormality, one grew slowly). Conclusions:The application of CMA in the prenatal diagnosis of 22q11.21 microdeletion and microduplication fetuses, and the comprehensive analysis of clinical manifestations and pregnancy outcome combined with ultrasonic diagnosis are of great significance in guiding the treatment and rehabilitation after birth of an affected child. Genetic counseling for cases with 22q11.21 microdeletion and microduplication syndrome should be cautious and consider ultrasound findings.