7p22.1 microduplication syndrome : clinical and molecular characterization of an adult case and review of the literature

A new 7p22.1 microduplication syndrome characterized by intellectual disability, speech delay and craniofacial dysmorphisms, such as macrocephaly, hypertelorism and ear anomalies, has been outlined by the description of two patients with interstitial microduplications confined to 7p22.1 and the recently defined minimal overlapping 430kb critical region including five genes. Here we report on the first adult patient aged 35 years with moderate intellectual disability, psychomotor delay, facial dysmorphisms, cryptorchidism and cardiac anomalies, who carries two close microduplications at 7p22.1 of about 900 and 150kb, respectively. The proximal smaller duplication includes three coding genes and maps outside the minimal described overlapping duplicated region, while the larger one represents the smallest 7p22.1 microduplication reported so far, as it encompasses the entire minimal region with only four additional genes. We compare the phenotype of our patient with that of the few reported cases and discuss on candidate genes in order to enhance the knowledge on genotype-phenotype correlation in 7p22.1 duplication syndrome.