Homozygous familial hypercholesterolemia (HoFH), a rare inherited disorder caused by bi-allelic mutations in the LDL Receptor pathway, is characterized by extremely elevated levels of low-density lipoprotein cholesterol (LDL-C) from birth and premature atherosclerotic cardiovascular disease (ASCVD). Our current knowledge about HoFH is disjointed and largely stems from relatively small case series and expert opinion. HICC (Homozygous FH International Clinical Collaborators) is a global consortium of clinicians who are contributing de-identified data of patients diagnosed with HoFH with the goal to advance our understanding of this rare disease.