Duplication of the Miller-Dieker Critical Region in a Patient with a Subtelomeric Unbalanced Translocation...

Submicroscopic duplications in the Miller-Dieker critical region have been recently described as new genomic disorders. To date, only a few cases have been reported with overlapping 17p13.3 duplications in this region. Also, small deletions that affect chromosome region 10p14→pter are rarely described in the literature. In this study, we describe, to our knowledge for the first time, a 5-year-old female patient with intellectual disability who has an unbalanced 10;17 translocation inherited from the father. The girl was diagnosed by subtelomeric FISH and array-CGH, showing a 4.43-Mb heterozygous deletion on chromosome 10p that involved 14 genes and a 3.22-Mb single-copy gain on chromosome 17p, which includes the critical region of the Miller-Dieker syndrome and 61 genes. The patient's karyotype was established as 46,XX.arr 10p15.3p15.1(138,206-4,574,436)x1,17p13.3(87,009-3,312,600)x3. Because our patient exhibits a combination of 2 imbalances, she has phenotypic features of both chromosome abnormalities, which have been reported separately. Interestingly, the majority of patients who carry the deletion 10p have visual and auditory deficiencies that are attributed to loss of the GATA3 gene. However, our patient also presents severe hearing and visual problems even though GATA3 is present, suggesting the involvement of different genes that affect the development of the visual and auditory systems.