The type of LDLR gene mutation predicts cardiovascular risk in children with familial hypercholesterolemia.
OBJECTIVE
To ascertain whether the molecular characterization of a defect in the low-density lipoprotein (LDL) receptor gene (LDLR) in children with heterozygous familial hypercholesterolemia (heFH) identifies subjects at greater risk of developing premature coronary artery disease (pCAD) later in life.


METHODS
We investigated 264 children with heFH from 201 families, along with 148 affected parents and 100 unaffected siblings. The lipid profile was assessed before any treatment was provided, and genotype analysis was performed to characterize LDLR defects. In a subgroup of children with heFH and controls, we measured aorta and carotid intima-media thickness (aIMT and cIMT). The prevalence of pCAD in parents and/or grandparents with heFH was recorded.


RESULTS
The children with heFH with a family history of pCAD had higher LDL cholesterol and apolipoprotein B levels and greater aIMT and cIMT than those with negative family history. Compared with carriers of LDLR-defective mutations, carriers of LDLR-negative mutations had a more severe phenotype, in terms of plasma lipid levels and IMT, and a higher prevalence of pCAD in first-degree relatives (36% vs 6.7%; P < .001).


CONCLUSIONS
The study of heFH in children, in which other risk factors for CAD play a minor role, allows early identification of those at increased risk for developing pCAD, who merit more stringent clinical control and early pharmacologic treatment.
Guardamagna
Ornella
O
Department of Pediatrics, University of Turin, Turin, Italy. ornella.guardamagna@unito.it
Restagno
Gabriella
G
Rolfo
Elio
E
Pederiva
Cristina
C
Martini
Scipione
S
Abello
Francesca
F
Baracco
Viviana
V
Pisciotta
Livia
L
Pino
Elisabetta
E
Calandra
Sebastiano
S
Bertolini
Stefano
S
D000293:Adolescent; D000328:Adult; D001011:Aorta / Q000473:pathology; D001055:Apolipoproteins B / Q000097:blood; D002339:Carotid Arteries / Q000473:pathology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003324:Coronary Artery Disease / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000235:genetics*; D007223:Infant; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D012306:Risk; D017539:Tunica Intima / Q000473:pathology; D017540:Tunica Media / Q000473:pathology; D055815:Young Adult
D001055:Apolipoproteins B; D008078:Cholesterol, LDL; C514519:LDLR-related protein 1A, human; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D002784:Cholesterol