The Rhesus Most Probable Genotype Calculator (RhMPG) calculates the most statistically probable genetic makeup (genotype) of an individual's Rhesus blood group system based on their observable characteristics (phenotype). This is crucial for blood transfusion compatibility, pregnancy management, and understanding inheritance patterns.
Before using the tool, you need laboratory results showing which Rhesus antigens are present (+) or absent (-) on your red blood cells. This information typically comes from:
For each antigen (D, C, E, c, e), select either:
Simply click on the appropriate button for each antigen. The selected option will turn blue to confirm your selection.
Click the "Submit" button to generate the most probable genotype. The tool will display:
Input: D+, C+, E-, c+, e+
Output: Most probable genotype: R1r (DCe/dce)
Interpretation: This person has one chromosome with D, C, and e antigens, and another with d, c, and e antigens. This is one of the most common genotypes in the Caucasian population.
Input: D-, C-, E-, c+, e+
Output: Most probable genotype: rr (dce/dce)
Interpretation: This person lacks the D antigen entirely (Rh-negative) and is homozygous for the dce haplotype.
Input: D+, C+, E+, c-, e+
Output: Most probable genotype: R1Rz (DCe/DCE)
Interpretation: This represents a less common configuration where the person lacks the small c antigen.
The tool provides results in two standard notation systems:
| Fisher-Race Notation | Wiener Notation |
|---|---|
| DCe/dce | R1r |
| DCe/DCe | R1R1 |
| DcE/dce | R2r |
| dce/dce | rr |
Fisher-Race Notation: Uses letters (D/d, C/c, E/e) to represent genes. Written as two sets separated by a slash (e.g., DCe/dce), where each set represents one chromosome.
Wiener Notation: Uses shorthand symbols (R1, R2, R0, r, etc.). More compact but requires memorization. Commonly used in blood banking.
Solution: Double-check your phenotype input data. Ensure you've selected the correct + or - for each antigen. Remember that laboratory errors can occur, so verify your source data.
Solution: Some antigens can show variable expression. Weak or partial antigens may give different results in different tests. Consult with a medical professional for clarification.
Solution: Make sure you've selected a value (+ or -) for all five antigens before clicking Submit. The tool requires complete phenotype data to calculate the genotype.
A: The tool uses established population frequencies to determine the most statistically probable genotype. Accuracy is generally high for common phenotypes but may be limited for rare variants. For clinical purposes, molecular testing provides definitive results.
A: No. This tool is not designed or validated for paternity testing. Professional DNA testing is required for legal paternity determination. Blood group analysis can only exclude paternity in some cases, never confirm it.
A: Understanding your genotype helps predict inheritance patterns for your children, assess pregnancy risks for Hemolytic Disease of the Newborn (HDN), and ensure optimal blood matching for transfusions in complex cases.
A: Some phenotype combinations are extremely rare or may indicate unusual genetic variants. If you receive an error message, consult with a blood bank specialist or genetic counselor for further evaluation.
For more information about Rhesus blood groups and genetics:
Now that you understand how to use the tool, try the RhMPG Calculator with your phenotype data!