Given the probable association of clinical symptoms and genetic background discussed in the previous Figure, the question now is whether or how genetic screening may be of benefit in sorting out the molecular etiology of a presentation of severe FH and in reaching diagnostic and clinical decision points.

The Figure repeats the pedigree originally shown in Figure 1, and it can be seen that family history may sometimes be less than sufficiently informative.  In this particular clinical example, the patient's

• mother died either without ever having had her lipids checked or at least without any record of what they were;
  
  
• father has moderate hypercholesterolemia with a serum LDL-C level of 172 mg/dL, but this would not
  normally be classified as a level of hypercholesterolemia severe enough to be consistent with
  heterozygous FH or one of these other diagnoses;
  
  
• siblings' lipid levels are not diagnostic. 
  

Therefore for the clinician, this is an example of a patient where the pedigree does not provide clear evidence of simple dominant transmission of severe heterozygous FH.