<prompt> Loss of heterozygosity associated withAcute myeloid leukemiaALLRetinoblastomaPromyelocytic leukaemia  <response>: Ref Robbins 9e p292_293 familial case of retinoblastoma 1 defective and 1 normal gene at bih heterozygous second mutation causes both genes to be defective loss of heterozygosity Increased chances of cancer sporadic case of retinoblastoma both normal gene at bih _ homogeneous normal genes Both mutations occur somatic Ally within a single cell homozygous abnormal genes increased chances of cancer 