Objective: To perform prenatal diagnosis, pedigree analysis, and genetic counseling of a pregnant woman who gave birth to a child with Kleefstra syndrome.
Methods: Karyotype analysis, chromosomal microarray analysis (CMA), multiplex ligation-dependent probe amplification (MLPA) and fluorescence in situ hybridization (FISH) were used of peripheral blood and amniotic fluid to find causes. Recurrence risk assessment was performed later.
Results: The amniotic fluid sample showed a 9q34.3 microduplication of arr (hg19) 9q34.3 (140 168 806-141 020 389)× 3, which overlapped the 9q34.3 microdeletion region of proband. The pregnant woman was detected with a balanced translocation of ish, t(9;17)(9q34.3; qter) (9p+; 17p+,9q+, 17q+). No other abnormal results were found in the family.
Conclusion: Offspring who share the same chromosome segment deletion or duplication are always from parent who carries balanced chromosomal structural aberration.