We report a male patient, offspring of a consanguineous marriage between first cousins, with cognitive impairment, autistic-like behavior, deafness, postaxial polydactyly, and mild dysmorphic features. aCGH revealed a 600 kb homozygous deletion of 4p15.1 (from 33.553 to 34.159 Mb in NCBI36 hg18) encoding several transcripts of unknown function. Both parents are heterozygous for the deletion and the non-affected brother is homozygous for the normal alleles. We hypothesize that this deletion is likely to contribute to the phenotype of the patient. This case underlines the contribution of aCGH in discovering potentially pathogenic CNVs in consanguineous matings.