Identification of a De Novo Deletion by Using A-CGH Involving PLNAX2: An Interesting Candidate Gene in Psychomotor Developmental Delay

Psychomotor developmental delay is a disorder with a prevalence of 12-18% in the pediatric population, characterized by the non-acquisition of motor, cognitive and communication skills during the child's development, in relation to chronological age. An appropriate neuropsychomotor evaluation and the use of new technologies, such as Array Comparative Genomic Hybridization (a-CGH) and Next-generation sequencing (NGS), can contribute to early diagnosis and improving the quality of life. In this case, we have analyzed a boy aged 2 years and 8 months, with a diagnosis of psychomotor developmental delay, mainly in the area of communication and language. The a-CGH analysis identified three de novo deletions of uncertain clinical significance, involving PLXNA2 (1q32.2), PRELID2, GRXCR2 and SH3RF2 (5q32), RIMS1 (6q13), and a heterozygous duplication of maternal origin involved three genes: HELZ, PSMD12 and PITPNC1 (17q24.2). Among all these alterations, our attention focused on the PLXNA2 gene because of the central function that plexin 2 carries out in the development of the central nervous system. However, all genes detected in the analysis could contribute to the phenotypic characteristics of the patient.