5p13 microduplication syndrome: A new case and better clinical definition of the syndrome

Chromosome 5p13 duplication syndrome (OMIM #613174), a contiguous gene syndrome involving duplication of several genes on chromosome 5p13 including NIPBL (OMIM 608667), has been described in rare patients with developmental delay and learning disability, behavioral problems and peculiar facial dysmorphisms. 5p13 duplications described so far present with variable sizes, from 0.25 to 13.6 Mb, and contain a variable number of genes. Here we report another patient with 5p13 duplication syndrome including NIPBL gene only. Proband's phenotype overlapped that reported in patients with 5p13 microduplication syndrome and especially that of subjects with smaller duplications. Moreover, we better define genotype–phenotype relationship associated with this duplication and confirmed that NIPBL was likely the major dosage sensitive gene for the 5p13 microduplication phenotype.

► 5p13 duplications may have different size and contain a variable number of genes.
► We report on a patient with a 5p13 duplication.
► We characterize this imbalance at molecular level.
► We confirm NIPBL is the major dosage sensitive gene for the 5p13 microduplication.