ABCMdb

PMID: 9375855

Casals T, Pacheco P, Barreto C, Gimenez J, Ramos MD, Pereira S, Pinheiro JA, Cobos N, Curvelo A, Vazquez C, Rocha H, Seculi JL, Perez E, Dapena J, Carrilho E, Duarte A, Palacio AM, Nunes V, Lavinha J, Estivill X
Missense mutation R1066C in the second transmembrane domain of CFTR causes a severe cystic fibrosis phenotype: study of 19 heterozygous and 2 homozygous patients.
Hum Mutat. 1997;10(5):387-92., [PubMed]

Sentences

No. Mutations Sentence Comment

0 ABCC7 p.Arg1066Cys HUMAN MUTATION 10:387392 (1997) (c) 1997 WILEY-LISS, INC. HUMU 822 RESEARCH ARTICLE Missense Mutation R1066C in the Second Transmembrane Domain of CFTR Causes a Severe Cystic Fibrosis Phenotype: Study of 19 Heterozygous and 2 Homozygous Patients T. Casals,1 P. Pacheco,2 C. Barreto,3 J. Giménez,1 M.D. Ramos,1 S. Pereira,4 J.A. Pinheiro,5 N. Cobos,6 A. Curvelo,7 C. Vázquez,8 H. Rocha,9 J.L. Séculi,10 E. Pérez,11 J. Dapena,12 E. Carrilho,3 A. Duarte,2 A.M. Palacio,13 V. Nunes,1 J. Lavinha,2 and X. Estivill1* 1 Molecular Genetics Department (IRO), Hospital Duran I Reynals, Barcelona, Spain 2 Departamento de Genética Humana, Instituto Nacional de Saúde, Lisboa, Portugal 3 Unidade de Fibrose Quística, Servico de Pediatria, Hospital Sta. Maria, Lisboa, Portugal 4 Genetics Department, Hospital Materno Infantil, La Coruña, Spain 5 Unidade de Fibrose Quística, Hospital Pediátrico, Coimbra, Portugal 6 Cystic Fibrosis Unit, Hospital Infantil Vall d`Hebron, Barcelona, Spain 7 Hospital de Dona Estefania, Lisboa, Portugal 8 Cystic Fibrosis Unit, Hospital de Cruces, Barakaldo, Spain 9 Unidade de Gastroenterologia, Hospital Dona Maria Pia, Porto, Portugal 10 Cystic Fibrosis Unit, Hospital S. Joan de Deu, Barcelona, Spain 11 Cystic Fibrosis Unit, Hospital Materno Infantil, Málaga, Spain 12 Cystic Fibrosis Unit, Hospital Virgen del Rocio, Sevilla, Spain 13 Centro de Analisis Geneticos (CAGT), Zaragoza, Spain Communicated by Robert Williamson We report the clinical features of 21 unrelated cystic fibrosis (CF) patients from Portugal and Spain, who carry the mutation R1066C in the CFTR gene. Login to comment 1 ABCC7 p.Arg1066Cys The current age of the patients was higher in the R1066C/any mutation group (P < 0.01), as compared to the aF508/aF508 group. Login to comment 2 ABCC7 p.Arg1066Cys Poor values for lung radiological involvement (Chrispin-Norman) and general status (Shwachman-Kulcycki) were observed in the R1066C/any mutation group (P < 0.005 and P < 0.0004). Login to comment 3 ABCC7 p.Arg1066Cys A slightly, but not significantly worse lung function was found in the R1066C/any mutation group when compared with the aF508/aF508 patients. Login to comment 6 ABCC7 p.Arg1066Cys The proportion of patients with lung colonization by bacterial pathogens was slightly, but not significantly higher in the R1066C/any mutation group (70.0%), as compared with the aF508/aF508 group (57.5%). Login to comment 7 ABCC7 p.Arg1066Cys Other clinical complications were significantly more frequent in the R1066C/any mutation patients(P < 0.02) than in the aF508/aF508 group. Login to comment 8 ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys The two homozygous R1066C/R1066C patients died at the ages of 3 months and 7 years. Login to comment 9 ABCC7 p.Arg1066Cys The data presented in this study clearly demonstrate that the R1066C mutation is responsible for a severe phenotype similar to that observed in homozygous aF508 patients. Login to comment 10 ABCC7 p.Arg1066Cys The poor clinical scores and complications of patients with the R1066C mutation are probably related to their slightly longer survival. Login to comment 12 ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys (c) 1997 Wiley-Liss, Inc. KEY WORDS: cystic fibrosis; R1066C mutation; genotype/phenotype correlation INTRODUCTION: R1066C MUTATION STUDY Cystic fibrosis (CF) is a multisystemic disorder with a wide clinical presentation involving the pulmonary, digestive, and reproductive systems (Welsh et al., 1995). Login to comment 29 ABCC7 p.Arg1066Cys We present here a phenotype/genotype correlation analysis of 21 unrelated CF patients (from a total of 28 identified) with mutation R1066C in the second MSD of CFTR. Login to comment 31 ABCC7 p.Arg1066Cys The study clearly demonstrates that the R1066C mutation is responsible for a severe phenotype similar to that observed in the homozygous ∆F508 patients. Login to comment 37 ABCC7 p.Arg1066Cys This allowed the detection of mutation R1066C in the different samples. Login to comment 38 ABCC7 p.Arg1066Cys Also, the microsatellite haplotype for the repeats IVS8CA, IVS17bTA, and IVS17bCA was analyzed, which facilitated the identification of several cases of mutation R1066C, as described (Morral et al., 1993). Login to comment 40 ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys The specific analysis of the R1066C mutation was performed by PCR amplification using primer 17bi5´ (Zielenski et al., 1991) and the mutagenesis primer 17bRx1: 5´ GCTGCCGTCCGAAGGCT*C 3´, that creates a restriction site for TaqI if the R1066C mutation is present (*indicates the modified nucleotide). Login to comment 42 ABCC7 p.Arg1066Cys Statistical Analysis Current age, age at diagnosis, sweat C1- test, percentile of height, percentile of weight, Chrispin- Norman score, Shwachman-Kulcycki score, FEV1 and FVC were compared between the R1066C/any mutation and the∆F508/∆F508 genotype groups using the Student unpaired t-test for continuous variables. Login to comment 44 ABCC7 p.Arg1066Cys RESULTS Twenty-eight CF patients with mutation R1066C were detected in Portuguese (13 patients) and Spanish (15 patients) CF patient populations. Login to comment 45 ABCC7 p.Arg1066Cys Seventeen patients were R1066C/∆F508 heterozygotes, five of them were deceased, two shortly after birth, one at 5 years of age (not included in Table 1), and two others at the ages of 7 and 24 years. Login to comment 46 ABCC7 p.Arg334Trp ABCC7 p.Gly542* Nine patients were heterozygous for five different mutations: R334W, G542X (1 sib deceased), 712-1G→T (1 sib deceased), 711+1G→T (2 sibs deceased), and 3905insT (only one patient for each one of these five mutations is included in Table 1). Login to comment 47 ABCC7 p.Arg1066Cys Finally, two patients were homozygous for R1066C mutation and died at the ages of 3 months and 7 years (Fig. 1, Table 2). Login to comment 49 ABCC7 p.Arg1066Cys The data are presented as R1066C/any mutation (4 of which were deceased) and also includes the data obtained for 82 Spanish ∆F508/∆F508 patients used as a control (Estivill et al., 1995). Login to comment 51 ABCC7 p.Arg1066Cys Table 2 shows the clinical features of the two homozygous patients for the R1066C mutation, who died at the ages of 3 months and 7 years. Login to comment 52 ABCC7 p.Arg1066Cys The two families with the R1066C homozygous patients were consanguineous (Fig. 1). Login to comment 53 ABCC7 p.Arg1066Cys The microsatellite haplotype for IVS8CA, IVS17bTA, and IVS17bCA showed three different associations with mutation R1066C: 17-7-17 (6 chromosomes), 16-33-13 (3 chromosomes), and 16-3113 (1 chromosome). Login to comment 56 ABCC7 p.Arg117His ABCC7 p.Ala455Glu ABCC7 p.Arg334Trp ABCC7 p.Asn1303Lys ABCC7 p.Leu206Trp ABCC7 p.Gly85Glu The current clinical data for missense mutations derived from a relatively large number of cases are limited to a few mutations: N1303K (Osborne et al., 1992; CF genotype-phenotype Consortium 1993), R117H (CF genotype-phenotype Consortium 1993), P205S (Chillón et al., 1993), A455E (Gan et al., 1995), L206W (Desgeorges et al., 1995), R334W (Estivill et al., 1995), and G85E (Vázquez et al., 1996). Login to comment 57 ABCC7 p.Gly551Ser Data on homozygous patients for missense mutations have been obtained for G551S TABLE 1. Login to comment 58 ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys Comparison of Clinical Features Between Cystic Fibrosis Patients With R1066C/Any Mutation and ∆F508/∆F508 Genotype Parameter R1066C/anya ∆F508/∆508 No. Login to comment 59 ABCC7 p.Arg334Trp ABCC7 p.Gly542* ABCC7 p.Arg1066Cys of patients 21 82 Sex: female/male 10/11 36/46 Mean ± SD (no. studied) Mean ± SD (no. studied) Current age-year 11.05 ± 6.93 (21) P < 0.01 7.72 ± 5.26 (82) Age at diagnosis-year 2.57 ± 4.63 (21) 2.22 ± 2.91 (82) Sweat Cl-mEq/l 112.44 ± 28.80 (18) 104.40 ± 15.70 (80) %ile-height 32.19 ± 35.03 (18) 30.70 ± 26.04 (80) %ile-weight 33.68 ± 35.95 (19) 27.99 ± 24.19 (80) Chrispin-Norman 12.50 ± 8.07 (12) P < 0.005 6.60 ± 6.26 (63) Shwachman-Kulcycki 69.46 ± 17.88 (15) P < 0.0004 83.11 ± 11.79 (72) FEV1-% predicted 64.06 ± 22.81 (15) 74.80 ± 23.06 (41) FVC-% predicted 72.20 ± 20.26 (15) 82.31 ± 20.03 (41) No. positive/no. studied (%) No. positive/no. studied (%) Lung colonization with 14/20 (70.0) 46/80 (57.5) bacterial pathogens Meconium ileus 1/21 (4.7) 9/81 (11.1) Dehydration 2/19 (10.5) 10/68 (14.7) Pancreatic insufficiency 21/21 (100.0) 79/81 (97.5) Other clinical features 13/21 (61.9) P < 0.02 29/82 (35.4) a Mutations were: ∆F508 (14 cases), R1066C (2), R334W (1), G542X (1), 712-1G>T (1), 711+1G>T (1), and 3905insT (1); FEV1, forced expiratory volume in 1 sec; FVC, forced vital capacity. Login to comment 60 ABCC7 p.Gly85Glu ABCC7 p.Ser549Asn ABCC7 p.Glu92Lys ABCC7 p.Ala559Thr ABCC7 p.Ile175Val (Strong et al., 1991), E92K (Nunes et al., 1993), S549N (Curtis et al., 1993), I175V (Romey et al., 1994), A559T (McDowell et al., 1995), and G85E (Vázquez et al., 1996). Login to comment 61 ABCC7 p.Arg334Trp ABCC7 p.Arg334Trp One example of the importance of the analysis of a large number of patients is mutation R334W, for which the study of a large number of patients has clearly defined R334W as a late onset PI mutation with inter-and intrafamilial variability (Estivill et al., 1995), whereas initial data (including functional studies) suggested that it was a PS mutation (Welsh and Smith, 1993). Login to comment 62 ABCC7 p.Arg1066Cys The analysis of the 19 patients heterozygous for mutation R1066C and the two homozygous patients provides useful clinical information on the severity of this mutation. Login to comment 63 ABCC7 p.Arg1066Cys No significant differences were detected concerning the age at diagnosis, sweat C1- values, and the percentiles of height and weight between the R1066C/any mutation group and the ∆F508/∆F508 group. Login to comment 64 ABCC7 p.Arg1066Cys The current age was significantly higher in the R1066C/any mutation group (P < 0.01), as compared with the ∆F508/∆F508 group. Login to comment 65 ABCC7 p.Arg1066Cys Worse values for lung radiological involvement (Chrispin-Norman) and general status (Shwachman-Kulcycki) were observed in the R1066C/any mutation group (P < 0.005 and P < 0.0004). Login to comment 66 ABCC7 p.Arg1066Cys A slightly worse, but not significantly, lung function was found in the R1066C/any mutation group when compared with the ∆F508/∆F508 patients. Login to comment 68 ABCC7 p.Arg1066Cys All the patients with the R1066C mutation were PI. Login to comment 69 ABCC7 p.Arg1066Cys The proportion of patients with lung colonization by bacterial pathogens was slightly higher, but not significantly, in the R1066C/any mutation group (70.0%) as compared with the ∆F508/∆F508 group (57.5%). Login to comment 70 ABCC7 p.Arg1066Cys Other clinical complications were significantly higher in the R1066C/any mutation patients (P < 0.02) than in the ∆F508/∆F508 group. Login to comment 73 ABCC7 p.Arg334Trp ABCC7 p.Gly542* ABCC7 p.Arg1066Cys In all the patients heterozygous for mutation R1066C, the second CF mutation can be considered as severe (∆F508, G542X, 712-1G→T, 711+1G→T, 3905insT, and R334W). Login to comment 74 ABCC7 p.Arg1066Cys Thus if the patients had a mild phenotype, this effect could be attributed to the R1066C mutation. Login to comment 76 ABCC7 p.Arg1066Cys Also, the two patients homozygous for mutation R1066C died at the ages of 3 months and 7 years old, which further confirms the involvement of this mutation in determining a severe phenotype. Login to comment 77 ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys Finally, of the 28 patients identified with the R1066C, 11 were deceased between a few hours after birth and 24 years, with a mean age at death of 4.5 years, further supporting the severity of mutation R1066C. Login to comment 78 ABCC7 p.Arg1066Cys Mutation R1066C is an arginine to cysteine change due to a C→T transition at nucleotide position 3328 in exon 17b (MSD2) of the CFTR gene (Fanen et al., 1992). Login to comment 79 ABCC7 p.Arg1066Cys The three microsatellite haplotypes associated with mutation R1066C make mutation analysis based on microsatellites difficult as TABLE 2. Login to comment 80 ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Cys Clinical Features of Two Cystic Fibrosis Patients Homozygous for CFTR Mutation R1066C Parameter Patient 583 S 48P Genotype R1066C/R1066C R1066C/R1066C Sex male female Current age-year 0.25a 7.00a Age at diagnosis-year 0.16 2.00 Sweat Cl-mEq/l 100 75 %ile-height %ile-weight 3.9 (<3) Chrispin-Norman Shwachman-Kulcycki FEV1b -% predicted FVCc -% predicted Lung colonization no yes Meconium ileus no no Dehydration no no Pancreatic insufficiency yes yes Other clinical features a Patients deceased. Login to comment 84 ABCC7 p.Arg1066Cys Genealogies of nine families with CFTR mutation R1066C and deceased CF patients. Login to comment 85 ABCC7 p.Arg1066Cys A total of 11 CF patients bearing the R1066C mutation were deceased, including two homozygous patients. Login to comment 87 ABCC7 p.Arg1066Cys compared with other CF mutations (Morral et al., 1994), and it also might suggest that mutation R1066C has originated independently in different genetic backgrounds. Login to comment 88 ABCC7 p.Arg1066Leu ABCC7 p.Arg1066His Two other changes have been described in the same codon: R1066H, G→A at nucleotide 3329 (Férec et al., 1992); and R1066L, G→T at nucleotide 3329 (Mercier et al., 1993). Login to comment 91 ABCC7 p.Arg1066His Férec et al. (1992) described a R1066H/ 1078delT patient with PI. Login to comment 92 ABCC7 p.Arg1066Leu Mercier et al. (1993) identified a patient with the R1066L mutation and PI. Login to comment 93 ABCC7 p.Gly542* ABCC7 p.Arg1066Cys ABCC7 p.Arg1066His ABCC7 p.Arg1066His Brancolini et al. (1995) found three heterozygous patients: R1066H/1717-1G→A, R1066H/ G542X and R1066C/∆F508 all PS. Login to comment 94 ABCC7 p.Arg1066His Finally, Mercier et al. (1995) reported the R1066H mutation associated with male infertility. Login to comment 96 ABCC7 p.Arg1066Cys ABCC7 p.Arg1066Leu ABCC7 p.Arg1066His In the case of mutations at codon 1066, it is now clear that mutation R1066C is a severe CF mutation, but further patients with mutations R1066H and R1066L should be analyzed before conclusions could be made about the severity of mutations at codon 1066. Login to comment 97 ABCC7 p.Arg1066Cys Although it is clear that R1066C in the second MSD of CFTR is a severe mutation, the worse clinical phenotype of patients with this mutation could be due to a slightly longer survival of the patients. Login to comment