FH genetic testing: it can make a lifetime of difference for patients

Familial hypercholesterolemia (FH) refers to a group of genetic defects resulting in severe elevations of blood cholesterol levels and increased risk of premature coronary heart disease (CHD). These defects are found in the FH genes, LDL receptor (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9), and possibly others.

FH is one of the most common congenital metabolic disorders.1 The more common, heterozygous type of FH occurs in about 1 in 300 to 500 people; total cholesterol concentrations in are in the range of 350 mg/dL to 550 mg/dL. (The homozygous form is very rare, occurring in about 1 in 1,000 people.)

FH affects young family members as well as adults

Because FH has genetic origins, the hypercholesterolemia is present at an early age and can lead to premature CHD. FH is highly treatable with lipid-lowering medications, so an early diagnosis can mean lower risk of CHD later in life.

The problem: most FH goes undiagnosed. You can change that.

Today, FH is generally underdiagnosed and undertreated. In fact, 9 in 10 FH cases go undiagnosed1.

With the help of genetic testing, you can change that trend. Genetic testing for FH, from Quest, examines 3 actionable2-6 FH genes: LDLR, APOB, and PCSK9, to enable an early, definitive diagnosis of FH. Early testing, both in adults and in family members, through cascade screening, can lead to early diagnosis of FH and earlier treatment, which should lead to a long-term benefit for affected adults and their families. FH cascade screening is highly recommended to enable earlier insight and intervention.7

Diagnose today to treat tomorrow—and control risk long-term

The phenotypic diagnosis of FH in young family members is established with:9

  • 2 LDL-C levels (obtained at least 3 months apart) >190 mg/dl or >160 mg/dl, in the presence of a family history of severely elevated LDL-C levels or premature coronary artery disease in a first-degree relative
  • LDL-C >130 mg/dL if a parent has a documented FH gene mutation*

Lipid-lowering therapy before adulthood has been proven to be advantageous. In Wiegman, et al., (2015), patients who were treated from adolescence until age 30 years were event-free, while 7% of parents had experienced an event by that age. The authors concluded that if diagnosed and treated at an early age, individuals with FH can have a normal life expectancy.10 For patients who need additional lowering of LDL-C after being on a controlled diet and maximally tolerated statin therapy, consider PCSK9 inhibitors.11

Know sooner to make a long-term difference

FH testing from Quest Diagnostics provides actionable information that can lead to earlier treatment and a lower lifetime risk of cardiovascular disease. Please contact your Quest Diagnostics Sales Representative to learn more.

*These points are provided for informational purposes only and are not intended as medical advice. A physician's test selection and interpretation, diagnosis, and patient management decisions should be based on his/her education, clinical expertise, and assessment of the patient.

Learn More

Contact Quest Genomics Client Services to speak with a genetic counselor at 1.866.436.3463
 
Download a FH Clinical History Form
 
Download a cardiology genetics requisition form
 
 
Download the FH genetic screening brochure
 
Download the cardiology genetics testing and services overview brochure
 
Read about our advanced lipid and inflammation test panels

References

1.

Goldberg AC, Hopkins PN, Toth PP, et al. Familial hypercholesterolemia: screening, diagnosis and management of pediatric and adult patients. Clinical guidance from the National Lipid Association Expert Panel on Familial Hypercholesterolemia. J Clinical Lipidology. 2011;5,S1–S8.

2.

Varret M, Abifadel M, Rabès JP, Boileau C. Genetic heterogeneity of autosomal dominant hypercholesterolemia. Clin Genet. 2008;73:1–13.

3.

Ahmad Z, Adams-Huet B, Chen C, Garg A. Low prevalence of mutations in known loci for autosomal dominant hypercholesterolemia in a multiethnic patient cohort. Circ Cardiovasc Genet. 2012;5:666–75.

4.

Rader DJ, Cohen J, Hobbs HH. Monogenic hypercholesterolemia: new insights in pathogenesis and treatment. J Clin Invest. 2003;111:1795–804.

5.

Wang J, Ban MR, Hegele RA. Multiplex ligation-dependent probe amplification of LDLR enhances molecular diagnosis of familial hypercholesterolemia. J Lipid Res. 2005;46(2):366–72.

6.

Fouchier SW, Dallinga-Thie GM, Meijers JC, et al. Mutations in STAP1 are associated with autosomal dominant hypercholesterolemia. Circ Res. 2014;115:552–5.

7.

Centers for Disease Control and Prevention. Cascade screening for familial hypercholesterolemia in the United States: public health impact and challenges. Available at blogs.cdc.gov/genomics/2017/07/25/cascade_screening. Accessed September 29, 2017.

8.

Ned RM, Sijbrands EJG. Cascade screening for familial hypercholesterolemia (FH). Version 1. PLoS Curr. 2011 May 23; 3:RRN1238; doi: 10.1371/currents.RRN1238.

9.

Gidding SS, Wiegman A, Watts G, Chapman J. Pediatric familial hypercholesterolemia: expert analysis. American College of Cardiology. Available at www.acc.org/latest-in-cardiology/articles/2015/11/24/14/32/pediatric-familial-hypercholesterolemia. Accessed October 20, 2017.

10.

Wiegman A, Gidding SS, Watts GF, et al. Familial hypercholesterolaemia in children and adolescents: gaining decades of life by optimizing detection and treatment. Eur Heart J. 2015;36:2425–37.

11.

Chaudhary R, Garg J, Shah N, et al. PCSK9 inhibitors: A new era of lipid lowering therapy. World J Cardiol. 2017;9(2):76–91.