22q11.2 Microduplication in a patient with 19p13.12-13.13 deletion.

BACKGROUND

The chromosome 22q11.2 region microduplication has been described in patients with variable phenotypes. Here we present a 3-month-old girl with both 22q11.2 microduplication and 19p13.12-13.13 deletion. The presence of both genomic imbalances in one patient has not been previously reported in literature.

METHODS

A routine G-banding karyotype analysis was performed using peripheral lymphocytes. Chromosome microarray analysis (CMA) was done using Affymetrix CytoScan™ HD array.

RESULTS

The result of karyotyping showed that the patient is 46,XX,t(12;19)(q24.3;p13.1), but CMA detected a 2.8Mb microduplication within the region 22q11.2 (chr22: 18,648,866-21,465,659) and a 1.2Mb deletion on the chromosome 19at band p13.12-p13.13 (chr19: 13,107,938-14,337,347) in her genome, while no abnormalities were identified on 12q24.3. The 3-month-old girl presented with microcephaly, cleft palate, low set and retroverted ears, and facial dysmorphism which consisted of the following: a long narrow face, widely spaced eyes, downslanting palpebral fissures, broad nasal base, short philtrum, thin upper lip, and micro/retrognathia. She also had a congenital right pulmonary artery sling and tracheal stenosis and suffered from significant hypotonia and partial bilateral mixed hearing loss.

CONCLUSIONS

We report a case of 22q11.2 duplication syndrome with 19p13.12-13.13 deletion. Synergistic effect from the two genomic imbalances is likely responsible for the complicated clinical features observed in this patient.