17p13.1 microdeletion involving the TP53 gene in a boy presenting with mental retardation but no tumor.

We report on the diagnosis of a 17p13.1 deletion in a 10-year-old boy. The patient presented with mild developmental delay, facial dysmorphism, joint hyperlaxity, pes planus, hypermetropia, hearing loss, and achromic patches following the Blaschko's lines on the right part of the thorax. Chromosome R-banding was normal. Array CGH using a 244 K oligonucleotide array showed a homogeneous de novo 17p13.1 microdeletion of 400 kb involving TP53 and 25 other genes, including genes involved in brain function (EFNB3, FXR2). To our knowledge, six patients presenting with a constitutional 17p13.1 microdeletion involving the TP53 gene have been reported. We discuss the phenotype of this microdeletion and the genetic counseling issues, especially regarding the risk of cancer associated with the deletion of the TP53 gene.