Abstract: Consanguineous marriages are the crucial factors for several genetic disorders and dreadful syndromes which are the bases of morbidity and mortality in the human population. The genetic disorders are linked to abnormalities in either p or q arms of specific chromosomes. However, reports in the literature are not firm on specificity of phenotypic response to the precise genomic region. In view of a paucity of literature on the subject and the controversies arising with respect to the discordance in phenotypic response, this particular case was found interesting for a report in the literature. This is about a baby whose mother was married to her cousin (a consanguineous marriage). The parents had a family history of cerebral palsy and mental retardation. Genetic analysis of the baby showed deletion at 5p14 and the father had translocation between chromosome 5p13 and 10p14 while the mother was genetically normal. The baby was born healthy but had several complications, till he died at the age of 5. The different complications that the baby suffered included: delayed motor activity and developmental disabilities, psychological derrangement, mental retardation, frequent convulsions, microcephali, delayed speech and language development, dysmorphic face, low set ears and hyper reactivity. There was gross discordance in the specific genome region and the phenotypic observations which appears to be due to the interaction between different loci at 5p in addition to epigenetic influence.