OBJECTIVE: To explore the genetic etiology for a pregnant woman with a history of multiple adverse pregnancies and assess the phenotype-genotype correlation of 22q11.2 microduplication syndrome in her family. METHODS: Amniotic fluid sample was taken from a pregnant woman for whom non-invasive prenatal screening indicated chromosome 22 abnormalities in the fetus. Peripheral blood samples from the woman, her brother and parents were collected for high-throughput low-depth whole genome sequencing (CNV-seq). A pedigree traceability analysis of the results was conducted in conjunction with analysis of clinical manifestation. Relevant literature (from establishment to March 2025) was systematically searched. This study was approved by the Medical Ethics Committee of Mianyang Maternal and Child Health Care Hospital (Ethics No.: Lun Shen [2024]009). RESULTS: CNV-seq revealed that the fetus had harbored a 6.02 Mb duplication at 22q11.21q11.23. Karyotyping confirmed it as 46,X?dup(22)(q11.2). Pedigree verification demonstrated that the pregnant woman, her brother and mother had all carried the same duplication. Phenotypic analysis of the affected family members showed classic features of 22q11.2 microduplication syndrome, including hypernasal speech, low nasal bridge, congenital heart disease, and cognitive impairment. A total of 44 cases with full information (including three patients from this pedigree) were included in the analysis. The penetrance of 22q11.2 duplication was approximately 29.5% (13/44), and 52.3% (23/44) of the cases had inherited the variant from a phenotypically normal parent. CONCLUSION This study has identified the genetic basis for the woman's recurrent adverse pregnancies and phenotypic abnormalities in her family members. The scoliosis identified in her younger brother has not been previously reported, thereby may enrich the clinical phenotype of this syndrome. For fetuses identified with a 22q11.2 microduplication, detailed fetal imaging is recommended, and genetic counseling should be provided to the couples.
Humans ; Female ; Pregnancy ; Prenatal Diagnosis/methods* ; Chromosome Duplication/genetics* ; Male ; Pedigree ; DiGeorge Syndrome/diagnosis* ; Adult ; Chromosomes, Human, Pair 22/genetics* ; Abnormalities, Multiple