Algorithm for the diagnosis of patients with neurodevelopmental disorders and suspicion of a genetic syndrome.

The wide range of chromosome aberrations seen in neurodevelopmental disorders may not alwaysbe characterized by means of a chromosome analysis. The objective of this study was to determine the genetic etiology of these disorders in patients with congenital neurological conditions and clinical suspicion of a genetic disorder using a clinical and molecular testing algorithm. Among 111 studied children, 71 showed submicroscopic chromosome aberrations associated with microdeletion/microduplication syndromes: DiGeorge (22 cases), Prader-Willi (26 cases), Angelman (2 cases), Williams-Beuren (17 cases), Smith-Magenis (1 case), Miller-Dieker (1 case), and cri du chat syndrome (1 case). Additionally, a de novo trisomy 17p12p11.2 due to an unbalanced insertion into 5p13.1 was identified in a 3-year-old child. In most cases, the use of a clinical method together with molecular techniques, such as fluorescence in situ hybridization, has allowed to make an accurate diagnosis in patients and / or families with neurodevelopmental disorders.