[Improved identification for 5p deletion syndrome and partial trisomy 11q presented in a fetus by SNP array]

Abstract

Objective: To investigate the prenatal application of single nucleotide polymorphism array (SNP array) in the identification of 5p deletion syndrome with partial trisomy 11q.

Methods: G-banded karyotyping and SNP array were performed using amniocytes on a fetus with multiple malformations for the identification of chromosome abnormality. Furthermore, karyotyping was carried out on the parental peripheral blood specimens to ascertain the origin of chromosome abnormalities and then fluorescence in situ hybridization (FISH) was also utilized to confirm the results.

Results: Karyotype of amniocyte showed 46, XY, der(5) (?::p15 → qter). SNP array revealed a 13.907 Mb deletion at 5p15.33p15.2 (chr5: 113576-14020561), overlapping the region of 5p deletion syndrome, and a 18.254 Mb duplication at 11q23.3 q25 (chr11: 116684627-134938470), overlapping no known syndrome. Karyotype of the parents showed a normal 46,XX in mother and 46,XY,t(5;11)(p15;q23) in father. Three-color metaphase FISH analysis on paternal peripheral blood specimens also confirmed the paternal karyotyping result.

Conclusion: SNP array could uncover 5p deletion syndrome with partial trisomy 11q unidentified by G-banded karyotyping and accurately locate the genomic breakpoints, facilitating the mapping of pathogenic critical regions and the identification of candidate genes, also accumulating research data for genotype-phenotype study.