Familial combined hyperlipidemia: controversial aspects of its diagnosis and pathogenesis.

Familial combined hyperlipidemia is the most frequent cause of primary dyslipidemia in Mexico. Its manifestations include hypercholesterolemia, hypertriglyceridemia, or a combination of both. Despite its high frequency, a proper diagnosis is rarely made. Assessment of the lipid profiles of at least three first-degree relatives is necessary. The diagnosis of familial combined hyperlipidemia in a family not only leads to the identification of other affected family members but, more important, allows cardiovascular risk stratification of those affected. Prospective studies have confirmed the atherogenicity of the disease. A critical review of the current literature in this field is presented in this article. Although three screenings of the genome have been completed, the genes responsible for this disorder have not been identified. Limitations with respect to the characterization of affected subjects and the heterogeneity of the disease are among possible explanations. However, familial combined hyperlipidemia, because of its high prevalence, must be given greater priority. It represents a great challenge for physicians involved in the treatment of dyslipidemic patients.