# 2011 Language Strategy includes FCH

FCH is subsumed under a newly broadened definition for FH. We’re altering the definition of FH from the receptor mutation itself to the whole receptor pathway. But even that expansion does not include FCH. This is confirmed by the fact that prevalence of FCH is 1/100, whereas lumping the APOB, PCSK9, along with the LDLR mutations comes out to the 1/300.  If FCH were included with the new definition of “FH,” prevalence would be around 1/74 – an absurdity. Appropriately, there is no mention here of high triglyceride as a red flag for FCH – being consistent with the definition of FCH and the feature that distinguishes it from FH.  But when FCH and high triglyceride are mentioned, it is under the assumption that the FCH are FH. This is new and revealing. Also, 1 in 1,000,000 million homozygous is calculated through Hardy-Weinberg’s equation from the heterozygous’ 1/500, but we arrive at those rates only if we limit our FH definition to the LDLRmutations. On the other hand, the heterozygous can only be 1/300 if we add in the APOB and PCSK9 mutations. So, below, the FH in HoFH is limited to the LDLR mutations, while the FH in HeFH adds in the APOB and PCSK9. (As we will see later, HoFH will be re-defined to include the APOB and Compound Heterozygous FH.)