Prenatal diagnosis of paternal duplication of 11p15.5→14.3: Its implication of Beckwith–Wiedemann syndrome

Objective To characterize a prenatally detected chromosomal aberration with molecular cytogenetic approaches and explore its relationship with Beckwith–Wiedemann syndrome (BWS). Case report A 33-year-old woman, gravida 2, para 0, was referred to our prenatal clinic at 20+ weeks due to an abnormal amniocentesis karyotyping finding, which showed 46,XY,add(11)(q24.2)dn. The mother conceived through in vitro fertilization–intracytoplasmic sperm injection (IVF-ICSI), then embryo transfer. Fetal ultrasound revealed a left-sided congenital diaphragmatic hernia, overgrowth of the fetus, and an enlarged placenta. After genetic counseling and careful deliberation by the family, the pregnancy was subsequently terminated at 22+ weeks of gestation, delivering a fetus weighing 810 g (85^th to 90^th centile) and a placenta of 325 g (85^th to 90^th centile). To further delineate the nature of the rearrangement involved in the defective chromosome 11, repeat chromosomal analyses, including array comparative genomic hybridization (aCGH) test and quantitative fluorescence–polymerase chain reaction (QF-PCR) using short tandem repeat (STR) markers, were performed by sampling fetal tissue. The final result confirmed a diagnosis of 46,XY,del(11)(q24.3q25),dup(11)(p14.3p15.5). The abnormal chromosome 11 was inherited from the father and the duplicated segment involved 11p15.5, a critical imprinting region for BWS. Conclusion We presented a prenatally detected chromosomal aberration characterized by paternal duplication of chromosome 11p15.5, which strongly related to the phenotypic manifestation of BWS.