Challenging the diagnosis of Cystic Fibrosis in a patient carrying the 186-8T/C allelic variant in the CF Transmembrane Conductance Regulator gene

BMC Pulmonary Medicine

Paola Melotti³  Baroukh Maurice Assael³  Mario Buffelli¹  Chiara Angiari³  Claudio Sorio²  Jan Johansson²  Genny Verzè³  Sara Caldrer³ 

[1]Department of Neurological Sciences, Physiology Section, University of Verona School of Medicine, Verona, Italy

[2]Department of Pathology and Diagnostics, General Pathology Section, University of Verona School of Medicine, Verona, Italy

[3]Cystic Fibrosis Center, Azienda Ospedaliera di Verona, Verona, Italy

关键词: Cystic fibrosis conductance transmembrane regulator function;    Nasal potential difference measurements;    Mutation analysis;    Cystic Fibrosis Conductance Transmembrane Regulator;    Cystic Fibrosis;   

Others  :  866452
DOI  :  10.1186/1471-2466-14-44

 received in 2013-10-28, accepted in 2014-02-28,  发布年份 2014

【 摘 要 】

Background

This report describe for the first time a clinical case with a CFTR allelic variant 186-8T/C (c.54-8 T/C) in intron 1 of CFTR and underline the importance of applying a combination of genetic and functional tests to establish or exclude a diagnosis of Cystic Fibrosis. In this case the diagnostic algorithm proposed for CF has been successfully applied at our Center and previous CF diagnosis assigned in a different Center was not confirmed.

Case presentation

A 38 year-old Italian woman had been treated as affected by CF since 2010, following diagnosis based on sweat tests (reported values of 73 and 57 mEq/L) and a clinical history consistent with CF. No mutations were identified by first level of genetic analysis. Afterwards the patient referred to our center for assessing the relevance of these findings. The genetic variant 186-8T/C (c.54-8 T/C) in intron 1 of the CFTR gene was detected by sequencing. Low-level interstitial-alveolar infiltration was recorded by high-resolution computerized tomography. Lung function was normal and sputum and Broncho Alveolar Lavage cultures resulted bacteriologically negative. Sweat chloride levels was re-assessed and resulted with values of 57 and 35 mEq/L, with a borderline range between 40 and 60 mEq/L. Nasal Potential Difference measurements resulted in three reliable measurements consistent with a non-CF phenotype. Differential diagnosis with ciliary dyskinesia was excluded, as was exon 2 skipping of CFTR gene that might have caused a CFTR functional defect. Furthermore, single cell fluorescence analysis in response to cAMP agonists performed in patient’s monocytes overlapped those obtained in healthy donors.

Conclusion

We concluded that this patient was not affected by CF. This case highlights the need for referrals to highly specialized centers and the importance of combined functional and genetic tests in making a correct diagnosis. Moreover, we confirmed a correlation between NPD tracings and cell depolarization in monocytes providing a rationale for proposing the use of leukocytes as a potential support for CF diagnosis.

【 授权许可】

   
2014 Caldrer et al.; licensee BioMed Central Ltd.

【 图 表 】

【 参考文献 】

• [1]Fanen P, Ghanem N, Vidaud M, Besmond C, Martin J, Costes B, Plassa F, Goossens M: Molecular characterization of cystic fibrosis: 16 novel mutations identified by analysis of the whole cystic fibrosis conductance transmembrane regulator (CFTR) coding regions and splice site junctions. Genomics 1992, 13(3):770-776.
• [2]Classification of cystic fibrosis and related disorders J Cyst Fibros 2002, 1(1):5-8.
• [3]Bombieri C, Claustres M, De Boeck K, Derichs N, Dodge J, Girodon E, Sermet I, Schwarz M, Tzetis M, Wilschanski M, Bareil C, Bilton D, Castellani C, Cuppens H, Cutting GR, Drevínek P, Farrell P, Elborn JS, Jarvi K, Kerem B, Kerem E, Knowles M, Macek M Jr, Munck A, Radojkovic D, Seia M, Sheppard DN, Southern KW, Stuhrmann M, Tullis E, Zielenski J, Pignatti PF, Ferec C: Recommendations for the classification of diseases as CFTR-related disorders. J Cystic Fibrosis 2011, 10:S86-S102.
• [4]De Boeck K, Wilschanski M, Castellani C, Taylor C, Cuppens H, Dodge J, Sinaasappel M: Cystic fibrosis: terminology and diagnostic algorithms. Thorax 2006, 61(7):627-635.
• [5]Farrell PM, Rosenstein BJ, White TB, Accurso FJ, Castellani C, Cutting GR, Durie PR, LeGrys VA, Massie J, Parad RB, Rock MJ, Campbell PW III: Guidelines for Diagnosis of Cystic Fibrosis in Newborns through Older Adults: Cystic Fibrosis Foundation Consensus Report. J Pediatr 2008, 153(2):S4-S14.
• [6]Bronsveld I, Sinaasappel M, Southern KW, Sermet-Gaudelus I, Leal T, Melotti P, Ballmann M, Hjelte L, Middleton PG, De Boeck K, Wilschnski M: Evaluation of European protocols for measuring nasal potential differences. J Cystic Fibrosis 2009, 8(Supplement 2(0)):S10.
• [7]Wilschanski M, Famini H, Strauss-Liviatan N, Rivlin J, Blau H, Bibi H, Bentur L, Yahav Y, Springer H, Kramer MR, Klar A, Ilani A, Kerem B, Kerem E: Nasal potential difference measurements in patients with atypical cystic fibrosis. Eur Respir J 2001, 17(6):1208-1215.
• [8]Canani RB, Terrin G, Elce A, Pezzella V, Heinz-Erian P, Pedrolli A, Centenari C, Amato F, Tomaiuolo R, Calignano A, Troncone R, Castaldo G: Genotype-dependency of butyrate efficacy in children with congenital chloride diarrhea. Orphanet J Rare Dis 2013, 8(1):194. BioMed Central Full Text
• [9]Sorio C, Buffelli M, Angiari C, Ettorre M, Johansson J, Vezzalini M, Viviani L, Ricciardi M, Verze G, Assael BM, Melotti P: Defective CFTR expression and function are detectable in blood monocytes: development of a new blood test for cystic fibrosis. PLoS One 2011, 6(7):e22212.
• [10]Dekkers JF, Wiegerinck CL, de Jonge HR, Bronsveld I, Janssens HM, de Winter-de Groot KM, Brandsma AM, de Jong NW, Bijvelds MJ, Scholte BJ, Nieuwenhuis EES, van den Brink S, Clevers H, van der Ent CK, Middendorp S, Beekman JM: A functional CFTR assay using primary cystic fibrosis intestinal organoids. Nat Med 2013, 19(7):939-945.
• [11]Gibson LE, Cooke RE: A test for concentration of electrolytes in sweat in cystic fibrosis of the pancreas utilizing pilocarpine by iontophoresis. Pediatrics 1959, 23(3):545-549.
• [12]Highsmith WE, Burch LH, Zhou Z, Olsen JC, Boat TE, Spock A, Gorvoy JD, Quittel L, Friedman KJ, Silverman LM, Boucher RC, Knowles MR: A novel mutation in the cystic fibrosis gene in patients with pulmonary disease but normal sweat chloride concentrations. N Engl J Med 1994, 331(15):974-980.
• [13]Correlation between genotype and phenotype in patients with cystic fibrosis. The Cystic Fibrosis Genotype-Phenotype Consortium N Engl J Med 1993, 329(18):1308-1313.
• [14]Ferec C, Quere I, Audrezt MP, Verlingue C, Guillermit H, Mercier B: Mutation Details for c.54-13C>G. Cystic Fibrosis Mutation Database NEWSLETTER #50 1992 edition. 1992.
• [15]Casaulta C, Stirnimann A, Schoeni MH, Barben J: Sweat test in patients with glucose-6-phosphate-1-dehydrogenase deficiency. Arch Dis Child 2008, 93(10):878-879.
• [16]Boucher RC: Bronchiectasis: a continuum of ion transport dysfunction or multiple hits? Am J Respir Crit Care Med 2010, 181(10):1017-1019.
• [17]Modiano G, Bombieri C, Ciminelli BM, Belpinati F, Giorgi S, Georges M, Scotet V, Pompei F, Ciccacci C, Guittard C, Pierre Audrézet M, Begnini A, Toepfer M, Macek M Jr, Ferec C, Claustres M, Pignatti PF: A large-scale study of the random variability of a coding sequence: a study on the CFTR gene. Eur J Hum Genet 2005, 13(2):184-192.
• [18]Spinelli E, Seia M, Melotti P, Marchina E, Padoan R: CFTR mutation in an Arab patient: clinical and functional features of 875 + 1G– > A/875 + 1G– > A genotype. J Cyst Fibros 2009, 8(4):282-284.
• [19]Cutting GR: Modifier genes in Mendelian disorders: the example of cystic fibrosis. Ann N Y Acad Sci 2010, 1214:57-69.
• [20]Stumpf A, Almaca J, Kunzelmann K, Wenners-Epping K, Huber SM, Haberle J, Falk S, Duebbers A, Walte M, Oberleithner H, Schillers H: IADS, a decomposition product of DIDS activates a cation conductance in Xenopus oocytes and human erythrocytes: new compound for the diagnosis of cystic fibrosis. Cell Physiol Biochem 2006, 18(4–5):243-252.
• [21]Derichs N, Sanz J, Von Kanel T, Stolpe C, Zapf A, Tummler B, Gallati S, Ballmann M: Intestinal current measurement for diagnostic classification of patients with questionable cystic fibrosis: validation and reference data. Thorax 2010, 65(7):594-599.