ABCMdb

PMID: 23082198

Sousa M, Servidoni MF, Vinagre AM, Ramalho AS, Bonadia LC, Felicio V, Ribeiro MA, Uliyakina I, Marson FA, Kmit A, Cardoso SR, Ribeiro JD, Bertuzzo CS, Sousa L, Kunzelmann K, Ribeiro AF, Amaral MD
Measurements of CFTR-Mediated Cl(-) Secretion in Human Rectal Biopsies Constitute a Robust Biomarker for Cystic Fibrosis Diagnosis and Prognosis.
PLoS One. 2012;7(10):e47708. doi: 10.1371/journal.pone.0047708. Epub 2012 Oct 17., [PubMed]

Sentences

No. Mutations Sentence Comment

64 ABCC7 p.Gly551Asp ABCC7 p.Arg553* ABCC7 p.Asn1303Lys ABCC7 p.Gly542* ABCC7 p.Arg1162* CFTR Genotyping Following screening of the 6 most common CFTR-disease causing mutations in the region of Campinas (Brazil) [27-29]: F508del, G551D, G542X, R1162X, N1303K, R553X, an extended CFTR mutation search (see Methods S1) was performed when only one/none mutation was found (Table S2, with both traditional and standard nomenclatures [30]). Login to comment 90 ABCC7 p.Ser549Arg One ''CF suspicion`` patient with severe CF symptoms and the F508del/S549R genotype, evidenced very low levels of CFTR function (,5% normalized to controls). Login to comment 92 ABCC7 p.Trp1282* ABCC7 p.Asp1152His In contrast, for the 28 individuals in the ''CF suspicion`` group who showed lumen-negative responses, i.e., normal CFTR function (Isc-CCH(IBMX/Fsk) = 2153.38615.33 mA/ cm2 vs Isc-CCH(IBMX/Fsk) = 2162.07619.64 mA/cm2 in the non-CF control group) we could only detect one CF-causing mutation (F508del) in one individual (being thus a CF-carrier) and 2 other mutations in two individuals who were thus compound heterozygous: W1282X/4428insGA and F508del/D1152H, respectively (Table S1). Login to comment 93 ABCC7 p.Asp1152His Based on their clinical characteristics (only obstructive azoospermia and bronchiectasis), values of CFTR colonic function (within the normal range) and CFTR genotypes, these two individuals were thus classified as CFTR-RD and both 4428insGA and D1152H were regarded as CFTR-RD mutations. Login to comment 103 ABCC7 p.Gly542* ABCC7 p.Gly576Ala ABCC7 p.Val562Ile As to the 5 individuals showing inconclusive Ussing chamber measurements, one individual had one CF-disease causing mutation (G542X) and two individuals had RD- related mutations (V562I and G576A). Login to comment 105 ABCC7 p.Gly542* ABCC7 p.Leu206Trp ABCC7 p.Leu206Trp ABCC7 p.Arg1066Cys ABCC7 p.Ile618Thr ABCC7 p.Ile618Thr Functional classification of rarer mutations also results from these analyses, namely (Table S1): 3120+1G.A as class I (2 siblings with 3120+1G.A/R1066C, absence of CFTR-function and severe phenotypes); 1716+18672A.G as class V (2 other siblings with F508del/1716+18672A.G, residual CFTR function 228-34%- and mild CF); I618T as class IV (in a patient with G542X/I618T, 37% CFTR function and mild disease); and L206W as class IV or CFTR-RD mutation (in a patient with F508del/L206W and the highest CFTR function 257%- and very mild disease). Login to comment 174 ABCC7 p.Ser549Arg For instance, we were able to detect very low function (,5% CFTR function vs non-CF controls) in a patient bearing S549R, recently described as Figure 4. Login to comment 180 ABCC7 p.Asp1152His doi:10.1371/journal.pone.0047708.g004 Class III [42], whereas significant CFTR-mediated Cl2 secretion was found in two patients bearing 4428insGA and D1152H (84 and 64%, respectively). Login to comment 188 ABCC7 p.Gly85Glu Interestingly, and corroborating such prediction among these four, there is a 19-year old patient with the F508del/G85E genotype, moderate PI (FEE = 103.89 mg/g) and ,12% of CFTR function (Fig.S2-C, Table S1) who recently (last 1K yr) started to progress from a relatively mild to moderate-severe lung disease, with five pulmonary exacerbations plus surgery to remove nasal polyps associated with a strong sinusitis. Login to comment 190 ABCC7 p.Ser549Arg For example, the patient with S549R could be tested ex vivo for the correction with the FDA-approved potentiator Ivacaftor, as suggested by the in vitro data [42]. Login to comment 208 ABCC7 p.Leu206Trp ABCC7 p.Gly85Glu Rectal biopsies from (A) Non-CF individual showing large cholinergic (carbachol, CCH, 100 mM, basolateral) and cAMP-dependent (3-isobutyl-1-methylxantine, IBMX, 100 mM, and forskolin, Fsk, 2 mM, basolateral) Chloride (Cl2 ) secretion (lumen-negative responses); (B) CF patient homozygous for F508del-CFTR mutation with absence of Cl2 secretion (only lumen-positive responses, reflecting potassium (K+ ) secretion, were observed); (C) CF patient (genotype: F508del/G85E-CFTR) showing very little (,12%) cAMP-dependent Cl2 secretion (biphasic responses observed upon co-cholinergic stimulation with CCH); and (D) CF patient (genotype: 3120+1G.A/L206W-CFTR) presenting larger CFTR residual function (,57%) and milder phenotype than in (C). Login to comment 209 ABCC7 p.Leu206Trp ABCC7 p.Gly85Glu Rectal biopsies from (A) Non-CF individual showing large cholinergic (carbachol, CCH, 100 mM, basolateral) and cAMP-dependent (3-isobutyl-1-methylxantine, IBMX, 100 mM, and forskolin, Fsk, 2 mM, basolateral) Chloride (Cl2 ) secretion (lumen-negative responses); (B) CF patient homozygous for F508del-CFTR mutation with absence of Cl2 secretion (only lumen-positive responses, reflecting potassium (K+ ) secretion, were observed); (C) CF patient (genotype: F508del/G85E-CFTR) showing very little (,12%) cAMP-dependent Cl2 secretion (biphasic responses observed upon co-cholinergic stimulation with CCH); and (D) CF patient (genotype: 3120+1G.A/L206W-CFTR) presenting larger CFTR residual function (,57%) and milder phenotype than in (C). Login to comment