Null Phenotypes

En(a-)

Absence of Glycophorin A

Mk

- null phenotype for MNS system

- null antigen for Glycophorin A & B

U

Absence of Glycophorin B

p

- P null

- AKA Anti-Tja

- causes spontaneous miscarriages, cytotoxic properties, binds compliment efficiently, wide thermal range

- absence of both transferases

- makes antibodies to P, P1 and Pk

Kell Null

- Mcleod syndrome

- acanthocytosis

- linked to Chronic Granulomatous Disease (CGD)

Jk Null

- inheritance of silent alleles

- null red cells resist 2M urea lysis (will not lyse like normal RBCs)

Duffy Null

- Fy (a-b-) = fy

- transcription stopped on red cells only

- very common among African American cells

- protection against P. vivax

Lub Null

- most commonly inherited from mutation in red cell promoter gene EKLF

- add antigens of Lutheran, P, and I groups onto the cells

- can come from lack of Lutheran gene

- makes Anti-Lu3

Gerbich Null

- leach type (Null) found in Papua New Guinea & Melanesia

- clinical elliptocytosis