HA-2 Genotype Positive

**Semantic type:** Laboratory or Test Result

**Definition:** A genetic finding indicating that a subject expresses the HA-2 genotype, which is defined as either homozygous or heterozygous expression of guanine at position 145 of the MYO1G gene, which encodes valine at amino acid residue 49 MYO1G(V). The MYO1G(V) form of unconventional myosin-Ig protein can be processed into a nonapeptide that can be presented by antigen expressing cells and recognized by HLA-A*0201 (HA-2+), while a variant MYO1G gene with adenine at position 145, which encodes a methionine at amino acid residue 49 (MYO1G(M)) does not produce a peptide that can be displayed by antigen presenting cells (HA-2-).

**Synonyms:** - HA-2 Positive - HA-2+/- or HA-2+/+ - HA-2+/- or HA-2+/+ Positive - HA2 Genotype Positive - HA2 Positive - HA2+/- or HA2+/+ - HA2+/- or HA2+/+ Positive - MYO1G(V) Genotype Positive - MYO1G(V) Positive - MYO1G(V/M) or (V/V) - MYO1G(V/M) or (V/V) Positive - Minor Histocompatibility Antigen HA-2 Genotype Positive