Prenatal diagnosis of 7q11.23 microdeletion: Two cases report and literature review

RATIONALE: Chromosome microdeletions within 7q11.23 can result in Williams-Beuren syndrome which is a rare autosomal dominant disorder. Williams-Beuren syndrome is usually associated with developmental delay, cardiovascular anomalies, mental retardation, and characteristic facial appearance. PATIENT CONCERNS: Two pregnant women underwent amniocentesis for cytogenetic analysis and chromosomal microarray analysis (CMA) because of abnormal ultrasound findings. Case 1 presented subependymal cyst and case 2 presented intrauterine growth restriction, persistent left superior vena cava and pericardial effusion in clinical ultrasound examination. DIAGNOSES: Cytogenetic examination showed that the 2 fetuses presented normal karyotypic results. CMA detected 1.536 Mb (case 1) and 1.409 Mb (case 2) microdeletions in the region of 7q11.23 separately. INTERVENTIONS: Both couples opted for the termination of pregnancies based upon genetic counseling. OUTCOMES: The deleted region in both fetuses overlapped with Williams-Beuren syndrome. To our knowledge, case 1 was the first reported fetus of Williams-Beuren syndrome with subependymal cyst. LESSONS: The genotype-phenotype of Williams-Beuren syndrome is complicated due to the phenotypic diversity. For prenatal cases, clinicians should consider the combination of ultrasonography, traditional cytogenetic, and molecular diagnosis technology when genetic counseling.