Prenatal diagnosis and genetic counselling of a de-novo 11p13p11.2 duplication with normal phenotype.

Background: Proximal 11p duplication is often derived from a balanced translocation in a parent or inherited from a carrier (father or mother) with normal phenotype, and part of this duplication is a de-novo mutation. The main clinical manifestations in carriers are: mental retardation, eye abnormalities such as abnormal optic nerve morphology, strabismus, hyperopia, nystagmus, and facial abnormalities such as wide nose bridge and tapered fingers.

Materials and methods: A woman underwent amniocentesis at 18 weeks of gestation because the additional report of noninvasive prenatal testing plus (NIPT-Plus) revealed 13-Mb duplication from 11p13 to 11p11.2.

Results: Chromosomal microarray analysis (CMA) on the uncultured amniocytes revealed a 12.57 Mb chromosomal duplication in the region of 11p13p11.2, ultrasound examination showed no dysmorphisms or intrauterine growth restriction in the fetus. At 40 weeks of gestation, the expectant mother gave birth vaginally to a male baby. The baby's growth parameters at birth were in the normal ranges. The baby received a complete physical examination, and the results were normal.

Conclusion: Combination of NIPT, prenatal ultrasound, karyotype analysis, CMA, and genetic counselling is helpful for the prenatal diagnosis of copy number variations.