Yes those last two in the chart are the two common ones that I have with 50% and 25% frequency respectively. They are known as secondary mutations and are known to reduce the activity of the enzyme even further if there are primary mutations. In one of the studied rare mutations (not the one I have) enzyme activity is reduced to 70% without the common mutation and 30% with. The rare mutation I have reduces the enzyme activity to somewhere between 10% - 20% by itself. I haven't been able to find what effect the common one has with my mutation but I am presuming it will also have some effect.