16p11.2 microdeletion syndrome: a case report

D. Dell’Edera, C. Dilucca, A. Allegretti, F. Simone, M. G. Lupo, C. Liccese, R. Davanzo

The recurrent ∼ 600 kb 16p11.2 microdeletion is among the most commonly known genetic etiologies of autism spectrum disorder, overweightness, and related neurodevelopmental disorders. Our patient is a 2-year-old white girl from the first pregnancy of a non-consanguineous healthy young white couple (father 33-years old and mother 29-years old). Our patient and her parents' DNA were analyzed by comparative genomic hybridization-array platform. Comparative genomic hybridization-array analysis highlighted a ∼ 600 kb deletion in 16p11.2 region. It has a segregant nature, since it was found in the mother and in her 2-year-old daughter. The microdeletion was confirmed by fluorescence in situ hybridization analysis. The presented clinical case is worthy of note since the observed microdeletion is often associated with a clinical phenotype tending to overweightness, but the proband (female) was hospitalized due to poor height and weight development, and anorexia. Moreover, the segregant nature of the observed genomic abnormality has to be noted, as well as the phenotypic variability between the mother and daughter. The case described here enriches the phenotypical spectrum linked to the 16p11.2 microdeletion. For these reasons, in the presence of a suspected genetic pathology it is fundamental to study the proband from the clinical point of view, to extend the clinical observation to the parents, and to provide a good family anamnesis. In this way, it is possible to reveal the presence of a familial genetic pathology whose phenotypical outcomes can be highly variable among the members of a family.