Non-Secretor
Definition
An individual homozygous for non-functional FUT2 alleles who produces no H, A, or B antigen in saliva, semen, or other exocrine secretions, despite having normal ABO antigens on red cells.
- Genetic basis
- Homozygous for non-functional FUT2 alleles
- Secretion antigens
- H, A, B antigens absent from saliva, semen, other secretions
- Red cell antigens
- Normal ABO expression unaffected
- Approximate population share
- Roughly one in five in many studied populations
Common questions
What is the forensic consequence of a stain coming from a non-secretor?+
ABO typing from saliva, semen, or other secretion-based stains fails to show blood group antigens even though the donor has a normal ABO blood type, so secretor-based grouping cannot be used to include or exclude that individual from such a stain.
How is secretor status actually determined in casework today?+
Historically it relied on absorption-inhibition tests on body fluid stains, but modern casework has largely moved to DNA-based typing (STR or SNP profiling), which does not depend on secretor status at all.
Related terms
- Blood-Group Substance
- Soluble ABO antigens (A substance, B substance, H substance) present in the body fluids of secretors. Chemically distinct from the glycolipid-bound cell-surface...
- FUT2 Gene
- The Fucosyltransferase 2 gene on chromosome 19q13, encoding the alpha-1,2-fucosyltransferase enzyme responsible for adding fucose to type-1 chain precursors in secretory tissues...
- Inhibition Index
- A quantitative measure of PCR inhibitor burden in a DNA extract, derived from the Ct shift of an internal positive control (IPC)...
- Se Gene / Se428
- The original notation for the secretor locus (Se for secretor, se or FUT2*428A for the non-secretor null allele carrying a nonsense mutation...
- Secretor
- An individual whose ABO blood group antigens are expressed on red blood cells and also released into body fluids such as saliva,...