The implication of genetics in psychiatric illnesses is not unique to schizophrenia, though the heritability of schizophrenia has been calculated as high as 80%. The continued research of the family following the discovery of the translocation yielded statistical analysis of the probability of observing the simultaneous occurrence, or co-inheritance, of psychological conditions and the translocation. This concept was measured quantitatively using the LOD, or logarithm of the odds value. The higher the LOD value, the stronger the correlation between the presence of the translocation and given disease(s) is thought to be. The LOD for the chromosome 1 translocation and identification of schizophrenia alone in the Scottish family was found to be 3.6. The LOD value of the translocation and a broader number of diagnoses (including schizophrenia, schizoaffective disorder, bipolar affective disorder, and recurrent major depression) was found to be 7.1.
