Cascade screening and genetic counseling differ for ARH as compared with FH, as the carrier of a pathogenic variant in the LDLRAP1 gene does not have marked total cholesterol and LDL-C elevations.
The objectives of the study were to improve the molecular diagnosis of familial hypercholesterolemia (FH) and to estimate the frequency of the ARH1 allele in 2 free-living Sicilian populations.
We recognized a 45-year-old Saudi female FH patient with double variants in the LDLR [c.1255 T > G, p.(Y419D)] and LDLRAP1 genes [c.604_605delTCinsA, p.(S202Tfs*2)].
Mutations in the low-density lipoprotein (LDLR), apolipoprotein B (APOB), proprotein convertase subtilisin/kexin 9 (PCSK9), and LDLRAP1 genes have been associated with FH.
This highlights the likelihood of a complex, polygenic inheritance of FH in Sri Lankan patients, indicating the need for a comprehensive genetic evaluation that includes the screening for mutations in other genes that cause FH, such as APOB, PCSK9, and LDLRAP1.
By the same combination of genetic linkage and molecular analysis we could also exclude mutations in the gene for the LDL receptor adaptor protein and in the gene for cholesterol-7-alpha-hydroxylase as causes of FH in our sample.