Peptide binding cleft is open end. Generally encode a chain and b microglobulin. Expressed as low concentration and less polymorphic. However several b chains are encoded by these regions. Class-I MHC Expressed by all nucleated cells.
Heterozygous animals express both maternal and paternal haplotypes.
Individuals expressing certain MHC alleles are susceptible to certain diseases. Autoimmune diseases Viral infections Disorders of complements Neurological disorders Allergies Depends on the relation between the frequency of that allele in certain diseases and frequency in general population. MHC allele frequency does not cause disease, may be due to related factors. In identical twin inheriting same risk factors, only one may develop disease. Susceptibility may be due to a particular MHC allele's responsiveness or unresponsiveness to a particular pathogen or an antigen.