Most normal individuals have the M phenotype (M,M1, or M2). Over 99% of M phenotypes are genotypically MM. In the absence of family studies, the phenotype (M) and quantitative level can be used to infer the genotype MM.

The most common alleles associated with a quantitatave deficiency ate Z and S. The reports for the rare alleles will indicate whether or not they have been associated with reduced quantitative levels.