Background: Trisomy 4p is a rare constitutional chromosomal rearrangement that leads to severe intellectual disability, characteristic facial features including a characteristic nose with a flat bridge and a bulbous tip (boxer nose), and extremities abnormalities. Pure trisomy 4p syndrome is due to duplication of the entire p arm of chromosome 4. Genotype-phenotype correlations in pure trisomy 4p cases are not well understood. Only five cases of pure trisomy 4p was previously reported in form of iso 4p, derivative formation and marker formation. Aim: Here, we present the clinical and laboratory findings of fifth case of pure trisomy 4p with interesting MRI manifestations. Results: Our patients' karyotype was defined as 47,XY,+(4)(pter→q11) mat that was inherited from his mother who had balanced translocation defined as 46, XX, t(4;12)(q12;q24.33). Conclusion: Our case is the sixth case of pure trisomy 4p and the 2nd report of pure trisomy 4p due to the presence of marker. Our findings emphasize and strengthen the clinical features of patients with pure trisomy 4p and add to few reported cases. More accurate clinical reports of patients with pure trisomy 4p is needed for more elucidation of the pathogenesis of pure trisomy 4p syndrome.