OBJECTIVE: To investigate the clinical characteristics and genetic etiology in a fetus with 12q14 microdeletion syndrome. METHODS: A fetus diagnosed with 12q14 microdeletion syndrome at Wenzhou People's Hospital in July 2019 was selected as the study subject. The fetus was from a twin pregnancy by in vitro fertilization-embryo transfer, with ultrasound findings including growth restriction, cleft lip/palate, ventricular septal defect, tricuspid regurgitation, and pericardial effusion. Clinical data and family history were collected. Amniotic fluid sample was collected from both twins, and peripheral blood samples were obtained from their parents. Amniocytic karyotyping analysis and chromosomal microarray analysis (CMA) were performed, and familial validation was conducted. This study was approved by the Medical Ethics Committee of Wenzhou People's Hospital (Ethics No.: KY-202408-034). RESULTS: Prenatal ultrasound showed no significant abnormality in one of the twins, whilst the other twin exhibited severe growth restriction accompanied by cleft lip/palate, ventricular septal defect, tricuspid regurgitation, and pericardial effusion. Karyotyping and CMA analyses of first twin showed no abnormalities, whilst the second twin had a chromosomal karyotype of 46,XN,t(3;12)(q26.3;q14), and CMA revealed a 4.9 Mb deletion in the 12q14.3-q15 region (arr[hg19]12q14.3q15(65,574,059_70,488,106)x1). Karyotyping and CMA analyses of both parents revealed no abnormalities, confirming that the fetus deletion was de novo in origin. Literature review suggested that prenatal diagnosis of 12q14 microdeletion syndrome has been extremely rare. CONCLUSION The fetus was diagnosed with 12q14 microdeletion syndrome. This de novo deletion may have dervied from chromosomal translocation. As a first-tier prenatal diagnostic technique, CMA can effectively detect microdeletion/microduplications missed by conventional karyotyping analysis.
Humans ; Female ; Pregnancy ; Chromosome Deletion ; Chromosomes, Human, Pair 12/genetics* ; Karyotyping ; Adult ; Prenatal Diagnosis ; Chromosome Disorders/diagnosis* ; Ultrasonography, Prenatal ; Fetus ; Male