Partial Trisomy 3p and Partial Monosomy 11q Associated with Atrial Septal Defect, Cleft Palate, and Developmental Delay: A Case Report

Unbalanced translocation involving both chromosome 3p duplication and 11q deletion in the same patient is extremely rare; only 1 live-born case was reported previously. This karyotype was also detected during prenatal diagnosis of 2 different pregnancies in a Taiwanese family which were both terminated. In all 3 cases, only standard karyotyping was done to detect the abnormal karyotypes. Here, we report a 4-year-old boy with cleft palate, atrial septal defect, and hypotonia with gross and fine motor delay. Oligonucleotide-based array comparative genomic hybridization showed copy number gain from 3pter to 3p24.2 (approximately 24.5 Mb) and copy number loss from 11q25 to 11qter (approximately 5.8 Mb). This de novo unbalanced translocation event involving a terminal 3p duplication and a terminal 11q deletion provides candidate genes for further investigation of dosage effect leading to the patient’s multiple phenotypic abnormalities. Genotype-phenotype correlation is difficult to make in this case due to the large number of genes involved. However, the description of such cases together with precise gene-level mapping of chromosomal breakpoints will add to further refinement of candidate genes to be investigated for terminal imbalances in 3p and 11q when more similar cases are reported.