A Connexin40 Mutation Associated With a Malignant Variant of Progressive Familial Heart Block Type I
Küçük Resim Yok
Tarih
2012
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Lippincott Williams & Wilkins
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Background-Progressive familial heart block type I (PFHBI) is a hereditary arrhythmia characterized by progressive conduction disturbances in the His-Purkinje system. PFHBI has been linked to genes such as SCN5A that influence cardiac excitability but not to genes that influence cell-to-cell communication. Our goal was to explore whether nucleotide substitutions in genes coding for connexin proteins would associate with clinical cases of PFHBI and if so, to establish a genotype-cell phenotype correlation for that mutation. Methods and Results-We screened 156 probands with PFHBI. In addition to 12 sodium channel mutations, we found a germ line GJA5 (connexin40 [Cx40]) mutation (Q58L) in 1 family. Heterologous expression of Cx40-Q58L in connexin-deficient neuroblastoma cells resulted in marked reduction of junctional conductance (Cx40-wild type [WT], 22.2 +/- 1.7 nS, n = 14; Cx40-Q58L, 0.56 +/- 0.34 nS, n = 14; P<0.001) and diffuse localization of immunoreactive proteins in the vicinity of the plasma membrane without formation of gap junctions. Heteromeric cotransfection of Cx40-WT and Cx40-Q58L resulted in homogenous distribution of proteins in the plasma membrane rather than in membrane plaques in approximate to 50% of cells; well-defined gap junctions were observed in other cells. Junctional conductance values correlated with the distribution of gap junction plaques. Conclusions-Mutation Cx40-Q58L impairs gap junction formation at cell-cell interfaces. This is the first demonstration of a germ line mutation in a connexin gene that associates with inherited ventricular arrhythmias and emphasizes the importance of Cx40 in normal propagation in the specialized conduction system. (Circ Arrhythm Electrophysiol. 2012; 5:163-172.)
Açıklama
Anahtar Kelimeler
heart block, genes, ion channels, death sudden, gap junctions
Kaynak
Circulation-Arrhythmia and Electrophysiology
WoS Q Değeri
Q1
Scopus Q Değeri
N/A
Cilt
5
Sayı
1
