Functional Characterization and Pharmacological Evaluation of a Novel GLA Missense Mutation Found in a Severely Affected Fabry Disease Family.

BACKGROUND: Fabry disease (FD) is a rare X-linked storage disorder resulting from the deficient activity of the lysosomal hydrolase α-galactosidase A (α-Gal A). Here we describe a 23-year-old man with FD possessing a novel mutation in the GLA gene, the evaluation of his family, and the functional characterization of the novel variant. METHODS: Two generations of a family were screened for FD by clinical symptoms and low enzymatic activity. This step was followed by DNA sequencing that showed a novel GLA missense mutation. To confirm the pathogenicity potential of the mutation, we employed site-directed polymerase chain reaction mutagenesis. GLA wild-type and mutant plasmids were transfected into mammalian cells; RNA and proteins were extracted for expression and analysis of enzymatic activity. RESULTS: The patient presents the variant p.Asn34Asp in the GLA and had several manifestations of FD since adolescence. The investigation of the deficiency of α-Gal A was initiated due to stage 4 of chronic kidney disease. All family members carrying the novel mutation presented early symptoms, including index case's mother, who received a renal transplant when she was 35 years old. In silico and in vitro analysis confirmed the pathogenic potential of the mutation p.Asn34Asp showing that the enzyme had only 4% of residual activity due to protein misfolding. The ability of the pharmacological chaperone 1-deoxygalactonojirimycin to recover the mutant was confirmed, producing 37.5% of residual activity. CONCLUSION: In this work, we present a novel missense mutation in GLA that leads to the production of a catalytically competent α-Gal A, which is degraded before its delivery to the lysosome, promoting severe manifestations of FD, with a very similar disease course in affected men and women.

Hypertension in patients on dialysis: diagnosis, mechanisms, and management / Hipertensão em pacientes em diálise: diagnóstico, mecanismos e tratamento

Abstract Hypertension (blood pressure > 140/90 mm Hg) is very common in patients undergoing regular dialysis, with a prevalence of 70-80%, and only the minority has adequate blood pressure (BP) control. In contrast to the unclear association of predialytic BP recordings with cardiovascular mortality, prospective studies showed that interdialytic BP, recorded as home BP or by ambulatory blood pressure monitoring in hemodialysis patients, associates more closely with mortality and cardiovascular events. Although BP is measured frequently in the dialysis treatment environment, aspects related to the measurement technique traditionally employed may be unsatisfactory. Several other tools are now available and being used in clinical trials and in clinical practice to evaluate and treat elevated BP in chronic kidney disease (CKD) patients. While we wait for the ongoing review of the CKD Blood Pressure KIDGO guidelines, there is no guideline for the dialysis population addressing this important issue. Thus, the objective of this review is to provide a critical analysis of the information available on the epidemiology, pathogenic mechanisms, and the main pillars involved in the management of blood pressure in stage 5-D CKD, based on current knowledge.

Resumo A hipertensão (pressão arterial > 140/90 mmHg) é muito comum em pacientes submetidos à diálise regular, com uma prevalência de 70-80%, e apenas a minoria tem controle adequado da pressão arterial (PA). Em contraste com a associação incerta entre de PA pré-dialítica com mortalidade cardiovascular, estudos prospectivos mostraram que a PA interdialítica, registrada como PA domiciliar ou pela monitorização ambulatorial da pressão arterial em pacientes em hemodiálise, está mais relacionada à mortalidade e eventos cardiovasculares. Embora a PA seja medida com frequência no ambiente de tratamento de diálise, aspectos relacionados à técnica de medição tradicionalmente empregada podem ser insatisfatórios. Várias outras ferramentas estão agora disponíveis, e estão sendo usadas em ensaios clínicos e na prática clínica para avaliar e tratar a PA elevada em pacientes com doença renal crônica (DRC). Enquanto esperamos pela revisão das diretrizes do KIDGO para a pressão sanguíneana DRC, não há nenhuma diretriz para a população em diálise abordando essa importante questão. Assim, o objetivo desta revisão é fornecer uma análise crítica das informações disponíveis sobre a epidemiologia, os mecanismos patogênicos e os principais pilares sustentadores do manejo da pressão arterial no estágio 5-D da DRC, com base no conhecimento atual.

Hypertension in patients on dialysis: diagnosis, mechanisms, and management.

Hypertension (blood pressure > 140/90 mm Hg) is very common in patients undergoing regular dialysis, with a prevalence of 70-80%, and only the minority has adequate blood pressure (BP) control. In contrast to the unclear association of predialytic BP recordings with cardiovascular mortality, prospective studies showed that interdialytic BP, recorded as home BP or by ambulatory blood pressure monitoring in hemodialysis patients, associates more closely with mortality and cardiovascular events. Although BP is measured frequently in the dialysis treatment environment, aspects related to the measurement technique traditionally employed may be unsatisfactory. Several other tools are now available and being used in clinical trials and in clinical practice to evaluate and treat elevated BP in chronic kidney disease (CKD) patients. While we wait for the ongoing review of the CKD Blood Pressure KIDGO guidelines, there is no guideline for the dialysis population addressing this important issue. Thus, the objective of this review is to provide a critical analysis of the information available on the epidemiology, pathogenic mechanisms, and the main pillars involved in the management of blood pressure in stage 5-D CKD, based on current knowledge.