| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 1.84 MB | Adobe PDF |
Orientador(es)
Resumo(s)
Background and Aims: Homozygous Familial Hypercholesterolemia (HoFH) is a rare, biallelic semidominant condition caused by pathogenic/likely pathogenic (P/LP) variants in LDLR, APOB, and/or PCSK9 genes. HoFH is characterized by a severe phenotype with LDL-C >400 mg/dL, xanthomas, and early-onset atherosclerotic cardiovascular disease (ASCVD). This work presents the clinical/genetic and follow-up data on individuals genetically identified with
HoFH.
Methods: A total of 1291 index-cases, with clinical diagnosis of FH, were referred to the Portuguese FH Study. Genetic diagnosis was performed using Sanger sequencing or NGS FH panel.
Results: Fifteen individuals were identified as HoFH: 5 with identical biallelic LDLR variants, 8 with different biallelic variants (7 in LDLR, 1 in PCSK9), and 2 with biallelic variants in LDLR and APOB (digenic). Most variants are classified as P/LP; 3 are variants of unknown significance (VUS), but exhibited defects in LDL receptor activity.
The cohort included mostly adults (73%) and females (87%), with a median age of 29.9±15.3years at referral (adults: 36.5±12.5years, children/adolescents: 12.0±1.9years). Clinical manifestations included tendon xanthomas (13%) and ASCVD (36%). At referral, all individuals were on statins therapy, with 50% using statin ezetimibe combination, 13% with PCSK9 inhibitors (PCSK9i), and 13% performed LDL apheresis. Five individuals carry at least one null allele (<10% activity), 9 carry defective alleles (10-70% activity), and one has null/null alleles. The latter presented the most severe phenotype (LDL-C=702mg/dL) despite intensive treatment (rosuvastatin, ezetimibe, LDL apheresis, and PCSK9i). Follow-up data were collected for 4 individuals: 2 with defective/defective alleles are now using PCSK9i, while 2 with null/defective and null/null are now using
ANGPTL3 inhibitors.
Conclusions: In general, Portuguese HoFH individuals are diagnosed late and do not reach the recommended target LDL-C levels. Genetic diagnosis enables precise identification of allele type, allowing more personalized therapeutic approaches, especially for null/null allele carriers who present reduced treatment responsiveness and require therapies independent of LDL receptor function.
Descrição
Palavras-chave
FH Familial Hyperchosterolemia Homozygous Genetic Diagnosis Portugal Doenças Cardio e Cérebro-vasculares
