Fibrosis quística en pacientes de la región centro-occidental venezolana: Identificación de focos geográficos

La Fibrosis Quistica (FQ) es una enfermedad genetica, causada por mutaciones en el gen de la proteina reguladora de la conductancia transmembrana (CFTR). Actualmente se han identificado mas de 1900 mutaciones, la mas comun es pF508del predominante en Europa. En Venezuela se han reportado pocas mutaciones: pF508del, pG542X, pR553X, 3120+1G'A. El objetivo del trabajo fue determinar la frecuencia de seis mutaciones del gen CFTR en pacientes de la region Centro-Occidental de Venezuela e identificar focos geograficos de la enfermedad. Se incluyeron sesenta pacientes no consanguineos, con caracteristicas clinicas consistentes con diagnostico de FQ y sesenta familiares sanos. Se revisaron las historias clinicas para investigar las variables: sexo, edad al momento del diagnostico, concentracion de cloruros en sudor, lugar de nacimiento del paciente y los abuelos. Una vez obtenido el consentimiento informado, se tomo una muestra de 2 mL de sangre para extraer ADN y se indagaron las mutaciones: pF508del, pG542X, pR553X, pG551D, pN1303K y pG85E. Las mutaciones encontradas y sus frecuencias fueron: pF508del (39,16 %), pG542X (4,17 %) y pR553X (2,50%); el 54,17% son mutaciones diferentes a las seis investigadas y se les denomino OTRA. Se identificaron siete genotipos, pero solo 25% son completos (pF508del/pF508del, pF508del/pG542X y pF508del/pR553X). Se identificaron quince focos geograficos de FQ ubicados en las regiones siguientes: a)Centro-Occidental (05), b)Centro-Norte Costera (03), c)Central (01), d)Sur-Oeste (03), e) Sur-Este (01) y f)Oriental (02). Estos resultados contribuyen a mejorar la calidad de vida de los pacientes y sus familias y son importantes para el Programa Nacional de FQ. The Cystic Fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator gene (CFTR). At present, more than 1900 mutations have been identified. The most common CFTR mutation is pF508del, it is predominant in Europe. Few mutations have been reported in Venezuela: pF508del, pG542X, pR553X, 3120+1G'A. The objective of this work was to determine the frequency of six CFTR mutations in patients from the Western Central Region of Venezuela and to identify CF geographical focuses. Sixty unrelated patients with clinical features consistent with CF diagnosis and sixty healthy relatives were included. The clinical records were reviewed to investigate: sex, age at diagnosis, sweat chloride values and birthplace of patients and grandparents. Two mL of whole blood samples were drawn from patients, after informed consent and DNA was extracted; the pF508del, pG542X, pR553X, pG551D, pN1303K and pG85E mutations were investigated. The mutations found and their frequency were: pF508del (39.16 %), pG542X (4.17 %) and pR553X (2.50%). There were 54.17% different mutations from the six investigated and they were called OTHER. Seven genotypes were identified, but only 25% are complete (pF508del/pF508del, pF508del/pG542X and pF508del/pR553X). Fifteen CF geographical focuses were identified, which are located in the following regions: a) Western Central (05), b) North Central Coast (03), c) Central (01), d) South-West (03), e) South-East (01), f) Oriental (02). The results of this research contribute to improve the quality of life in patients and their families, and they are important for the National CF Program.