Validity and Reliability of the Dutch Adaptation of the Actinic Keratosis Quality of Life Questionnaire (AKQoL).

BACKGROUND: The Actinic Keratosis Quality of Life Questionnaire (AKQoL) is a disease-specific instrument to measure the impact of actinic keratosis (AK) on patients' lives. OBJECTIVE: To validate and test the psychometric properties of the AKQoL translated into the Dutch language (AKQoL-NL). METHODS: All new patients ≥50 years of age with untreated AK in a university medical center and a general hospital between August 2014 and August 2015 were eligible. The AKQoL was obtained and repeated after 2 weeks. The feasibility was tested by missing responses and response distribution. The internal consistency reliability of each domain was investigated with the Cronbach alpha, and test-retest reliability and validity with the Spearman correlation coefficient. AKQoL scores were compared to the Skindex-17 for convergent validity and to the Groningen Frailty Indicator scores for divergent validity. RESULTS: A total of 153 of 190 eligible patients consented to participate. Feasibility analysis showed that none of the items missed ≥10% of responses but 5 of the 9 items showed floor effect. The AKQoL subscales showed a moderate internal consistency (Cronbach α = 0.235-0.468) and an excellent test-retest reliability (interclass correlation coefficient = 0.997-1). The AKQoL correlated poorly with the symptom component and moderately with the psychosocial component of the Skindex-17 (ρ = -0.015 to 0.346 and 0.324 to 0.501, respectively), which is less than expected. The AKQoL scored poorly in both of the Groningen Frailty Indicator (GFI) components (ρ = -0.97 to 0.12 and 0.185 to 0.276, respectively), as expected. CONCLUSION: The AKQoL-NL is a feasible, moderately valid, and moderately reliable health-related quality of life questionnaire.

Genetic variation in APOB, PCSK9, and ANGPTL3 in carriers of pathogenic autosomal dominant hypercholesterolemic mutations with unexpected low LDL-Cl Levels.

Autosomal Dominant Hypercholesterolemia (ADH) is caused by LDLR and APOB mutations. However, genetically diagnosed ADH patients do not always exhibit the expected hypercholesterolemic phenotype. Of 4,669 genetically diagnosed ADH patients, identified through the national identification screening program for ADH, 75 patients (1.6%) had LDL-cholesterol (LDL-C) levels below the 50th percentile for age and gender prior to lipid-lowering therapy. The genes encoding APOB, PCSK9, and ANGPTL3 were sequenced in these subjects to address whether monogenic dominant loss-of-function mutations underlie this paradoxical phenotype. APOB mutations, resulting in truncated APOB, were found in five (6.7%) probands, reducing LDL-C by 56%. Rare variants in PCSK9, and ANGPTL3 completely correcting the hypercholesterolemic phenotype were not found. The common variants p.N902N, c.3842+82T>A, p.D2312D, and p.E4181K in APOB, and c.1863+94A>G in PCSK9 were significantly more prevalent in our cohort compared to the general European population. Interestingly, 40% of our probands carried at least one minor allele for all four common APOB variants compared to 1.5% in the general European population. While we found a low prevalence of rare variants in our cohort, our data suggest that regions in proximity of the analyzed loci, and linked to specific common haplotypes, might harbor additional variants that correct an ADH phenotype.