The RH blood group system is the most polymorphic and immunogenic among blood groups. Variant Rh antigens have been found with high frequencies in African descendants persons. The DAR-ceAR haplotype results from the rearrangement of the RHCE gene with the internal sequences of the RHD gene that give rise to an altered Rh protein and may produce a clinically significant antibody. We report a case of anti-RH18 detected in a female patient with sickle cell trait. Serologic and molecular investigations were performed to identify RH variants from the propositus and her relatives. The results of genomic DNA analysis showed the propositus carrying the haplotype RHD*weak D 4.2.2/RHCE*ceAR, as well as her father and sister.