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  <link:roleRef roleURI="http://praxismedicines.com/role/SubsequentEventsTables" xlink:type="simple" xlink:href="prax-20201231.xsd#SubsequentEventsTables"/>
  <link:calculationLink xlink:role="http://praxismedicines.com/role/SubsequentEventsTables" xlink:type="extended"/>
  <link:roleRef roleURI="http://praxismedicines.com/role/SubsequentEventsDetails" xlink:type="simple" xlink:href="prax-20201231.xsd#SubsequentEventsDetails"/>
  <link:calculationLink xlink:role="http://praxismedicines.com/role/SubsequentEventsDetails" xlink:type="extended"/>
</link:linkbase>
