Journal of Pediatric Gastroenterology and NutritionVolume 39, Issue S1 p. S405-S406 ABSTRACTS: Poster Session Abstracts P0915 MECONIUM ILEUS IN CYSTIC FIBROSIS NEONATES IS ASSOCIATED WITH POLYMORPHIC MARKERS IN THE CALCIUM-ACTIVATED POTASSIUM CHANNEL (KCNN4) GENE J. Zielenski, J. Zielenski Genetics, The Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorD. Markiewicz, D. Markiewicz Genetics, The Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorX. Yuan, X. Yuan Genetics, The Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorM. Patel, M. Patel Genetics, The Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorL. Sun, L. Sun Statistics, University of Toronto, Toronto, CanadaSearch for more papers by this authorI. Aznarez, I. Aznarez Genetics, University of Toronto, Toronto, CanadaSearch for more papers by this authorL. Tsui, L. Tsui University of Hong-Kong, Hong-Kong, Hong Kong Special Administrative Region of ChinaSearch for more papers by this author J. Zielenski, J. Zielenski Genetics, The Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorD. Markiewicz, D. Markiewicz Genetics, The Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorX. Yuan, X. Yuan Genetics, The Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorM. Patel, M. Patel Genetics, The Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorL. Sun, L. Sun Statistics, University of Toronto, Toronto, CanadaSearch for more papers by this authorI. Aznarez, I. Aznarez Genetics, University of Toronto, Toronto, CanadaSearch for more papers by this authorL. Tsui, L. Tsui University of Hong-Kong, Hong-Kong, Hong Kong Special Administrative Region of ChinaSearch for more papers by this author First published: 01 June 2004 https://doi.org/10.1002/j.1536-4801.2004.tb13345.x Submitted by: [email protected] Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume39, IssueS1June 2004Pages S405-S406 RelatedInformation

Mutation detection in an integral part of disease diagnosis and patient study. For most Mendelian diseases, multiple mutations may be found in a single gene among a patient population. The type of mutations may vary from large deletions to single-base-pair (bp) substitutions, and different diseases may have different predominant types. For example, large deletions are often found in Duchenne muscular dystrophy () and truncation mutation is the predominant type in BRCA1-associated breast cancer (). Therefore, different mutation detection strategies are required for different diseases.

Cystic fibrosis (CF) is caused by mutations in the CFTR gene. The spectrum of CFTR mutations varies between populations and depends on different factors, such as ethnic background and geographical location. The extensive CFTR mutation screening of 129 patients with classical or atypical CF from the south-western region of Sweden revealed the presence of 37 CFTR mutations, including 12 novel alleles. The overall mutation detection rate in this study population was 92%, the highest among all tested regions in Sweden. Eight mutations with a frequency above 1% (DeltaF508, 394delTT, R117C, 3659delC, E60X, 1112delT, R764X, and 621 + 1G --> T) accounted for 78% of CF chromosomes and have been recommended for inclusion in the CFTR mutation screening panel for molecular diagnosis of CF in this region. The multiple occurrence of specific CFTR alleles less common than the predominant DeltaF508 mutation (394delTT, R117C, 3659delC) allowed for genotype-phenotype comparisons and revealed consistent relationships between these mutations and disease severity.

Human MutationVolume 10, Issue 3 p. 239-240 Mutations in Brief Two novel frameshift deletions (1924del7, 2055del9→A) in the CFTR gene in Mexican cystic fibrosis patients Lorena Orozco, Corresponding Author Lorena Orozco Molecular Biology Laboratory, Human Genetics Department, Instituto Nacional de Pediatría, Mexico City, MexicoMolecular Biology Laboratory, Human Genetics Department, Instituto Nacional de Pediatría, Mexico City, MexicoSearch for more papers by this authorJulian Zielenski, Julian Zielenski Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorDanuta Markiewicz, Danuta Markiewicz Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorTeresa Villarreal, Teresa Villarreal Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorLap-Chee Tsui, Lap-Chee Tsui Department of Genetics, Hospital for Sick Children, Toronto, Canada Department of Molecular and Medical Genetics, University of Toronto, Toronto, CanadaSearch for more papers by this authorJosé Luis Lezana, José Luis Lezana Asociación Mexicana de Fibrosis Quística, Mexico City, MexicoSearch for more papers by this authorRosa M del Angel, Rosa M del Angel Department of Experimental Pathology, CINVESTAV-IPN, Mexico City, MexicoSearch for more papers by this author Lorena Orozco, Corresponding Author Lorena Orozco Molecular Biology Laboratory, Human Genetics Department, Instituto Nacional de Pediatría, Mexico City, MexicoMolecular Biology Laboratory, Human Genetics Department, Instituto Nacional de Pediatría, Mexico City, MexicoSearch for more papers by this authorJulian Zielenski, Julian Zielenski Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorDanuta Markiewicz, Danuta Markiewicz Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorTeresa Villarreal, Teresa Villarreal Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorLap-Chee Tsui, Lap-Chee Tsui Department of Genetics, Hospital for Sick Children, Toronto, Canada Department of Molecular and Medical Genetics, University of Toronto, Toronto, CanadaSearch for more papers by this authorJosé Luis Lezana, José Luis Lezana Asociación Mexicana de Fibrosis Quística, Mexico City, MexicoSearch for more papers by this authorRosa M del Angel, Rosa M del Angel Department of Experimental Pathology, CINVESTAV-IPN, Mexico City, MexicoSearch for more papers by this author First published: 08 January 1999 https://doi.org/10.1002/(SICI)1098-1004(1997)10:3<239::AID-HUMU11>3.0.CO;2-0Citations: 3AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume10, Issue31997Pages 239-240 RelatedInformation

Human MutationVolume 9, Issue 2 p. 183-184 Mutations in Brief Identification of two mutations (S50Y and 4173delC) in the CFTR gene from patients with congenital bilateral absence of vas deferens (CBAVD) J Zielenski, J Zielenski Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorP Patrizio, P Patrizio Department of Obstetrics and Gynecology, University of California at Irvine, Orange, CaliforniaSearch for more papers by this authorD Markiewicz, D Markiewicz Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorRH Asch, RH Asch Department of Obstetrics and Gynecology, University of California at Irvine, Orange, CaliforniaSearch for more papers by this authorL-C Tsui, Corresponding Author L-C Tsui Department of Genetics, Hospital for Sick Children, Toronto, Canada Departments of Molecular and Medical Genetics, University of Toronto, Toronto, Canada M5G 1χ8; Fax: 416-813-4931Department of Genetics, Hospital for Sick Children, Toronto, Canada; Departments of Molecular and Medical Genetics, University of Toronto, Toronto, Canada M5G 1χ8; Fax: 416-813-4931Search for more papers by this author J Zielenski, J Zielenski Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorP Patrizio, P Patrizio Department of Obstetrics and Gynecology, University of California at Irvine, Orange, CaliforniaSearch for more papers by this authorD Markiewicz, D Markiewicz Department of Genetics, Hospital for Sick Children, Toronto, CanadaSearch for more papers by this authorRH Asch, RH Asch Department of Obstetrics and Gynecology, University of California at Irvine, Orange, CaliforniaSearch for more papers by this authorL-C Tsui, Corresponding Author L-C Tsui Department of Genetics, Hospital for Sick Children, Toronto, Canada Departments of Molecular and Medical Genetics, University of Toronto, Toronto, Canada M5G 1χ8; Fax: 416-813-4931Department of Genetics, Hospital for Sick Children, Toronto, Canada; Departments of Molecular and Medical Genetics, University of Toronto, Toronto, Canada M5G 1χ8; Fax: 416-813-4931Search for more papers by this author First published: 07 January 1999 https://doi.org/10.1002/(SICI)1098-1004(1997)9:2<183::AID-HUMU13>3.0.CO;2-ZCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. References Keen J, Lester D, Inglebearn, C, Curtis A, Bhattacharaya S (1991) Rapid detection of single base mismatches as heteroduplexes on Hydrolink gels. Trends Genet 7: 5. Tucker SJ, Tannahill D, Higgins CF (1992) Identification and development expression of the Xenopus laevis cystic fibrosis trans membrane conductance regulator gene. Hum Mol Genet 1: 77– 82. Zielenski J, Bozon D, Kerem BS, Markiewicz D, Durie P, Rommens J, Tsui L-C (1991a) Identification of mutations in exons 1 through 8 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Genomics 10: 229– 235. Zielenski J, Rozmahel R, Bozon D, Kerern B, Grzelczak Z, Riordan JR, Rommens JM, Tsui L-C (1991b) Genomic DNA sequence of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Genomics 10: 214– 228. Citing Literature Volume9, Issue21997Pages 183-184 ReferencesRelatedInformation

Six new mutations have been identified in the CFTR gene. These mutations, representing three different categories-missense (R31L, W1098R), nonsense (E1104X), and frameshift (441delA, 681delC, 1461ins4)-are located in exons 2, 4, 5, 9, and 17b of the gene and presumed to cause cystic fibrosis (CF) in patients. All these mutations are probably rare in the population, as no additional examples were found for any of them in a cohort of 545 CF patients. Our study also revealed a benign sequence variation (3499 + 45T-->C) in intron 17b. (C) 1995 Wiley-Liss, Inc.

OBJECTIVE:To compare differences in epithelial chloride conductance according to class of mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. METHODS:We evaluated the relationship between the functional classes of CFTR mutations and chloride conductance using the first diagnostic sweat chloride concentration in a large cystic fibrosis (CF) population. RESULTS:There was no difference in sweat chloride value value between classes of CFTR mutations that produce no protein (class I), fail to reach the apical membrane because of defective processing (class II), or produce protein that fails to respond to cyclic adenosine monophosphate (class III). Those mutations that produce a cyclic adenosine monophosphate-responsive channel with reduced conductance (class IV) were associated with a significantly lower, intermediate sweat chloride value. However, patients with the mutations that cause reduced synthesis or partially defective processing of normal CFTR (class V) had sweat chloride concentrations similar to those in classes I to III. CONCLUSION:Studies of differences in chloride conductance between functional classes of CFTR mutations provide insight into phenotypic expression of the disease.

A point mutation (1898+5G→T) located five base pairs downstream from the donor splice site in intron 12 of the CFTR gene has been identified in a consanguineous CF patient of Chinese origin. To determine if this nucleotide substitution could affect mRNA splicing, PCR analysis was performed with RNA isolated from the lymphoblastoid cell line of the mother of the deceased patient. While exon 12‐minus transcript was detected in this sample, it was also found in individuals without 1898+5G→T, albeit in a smaller proportion. Using a sequence polymorphism associated with each of the two alleles in the mother, however, we showed that mutant transcript was almost exclusively produced by the 1898+5G→T allele. Skipping of exon 12 would result in the deletion of 29 amino acids from the first nucleotide binding domain of CFTR, rendering the protein non‐functional. The possibility of a low level (2.5%) of normal transcript from the mutant allele cannot be excluded and it may explain the pancreatic sufficient phenotype of the patient. The 1898+5G→T mutation was found in two other CF patients of Chinese origin, but it was not detected in 192 CF chromosomes of Caucasian origin and 30 other chromosomes from Chinese individuals without a family history of CF.

Obstructive azoospermia due to congenital absence of vas deferens is a prominent clinical feature among male patients with cystic fibrosis (CF). A similar autosomal recessive condition with no other CF manifestations is classified as congenital bilateral absence of vas deferens (CBAVD). Since 50%-64% of CBAVD patients have been found to be positive for at least one known CFTR mutation, it is believed that at least part of the CBAVD population represents an atypical form of CF affecting only the male reproductive system. This explanation is not completely satisfactory, however, because only {approximately}10% of CBAVD patients are found to carry known CF mutations on both chromosomes, even after exhaustive screening of the entire CFTR coding region. Here we present data to show that a previously known sequence variant in intron 8 of the CFTR gene is a specific and frequent mutation associated with CBAVD. 20 refs., 1 tab.

We have analyzed the CFTR mRNA populations in a cystic fibrosis patient heterozygous for the 621 + 1G-->T and 711 + 1G-->T mutations. Total RNA isolated from the nasal epithelial cells and Epstein-Barr virus-transformed lymphoblasts derived from this patient was reversely transcribed and a region extending from exon 3 to exon 7 of the gene was amplified by the polymerase chain reaction and analyzed. Three abnormal products were identified, suggesting the presence of three aberrant transcripts, and their profiles were identical in both cell types. Two of the products were found to be missing either exon 4 or exon 5 as anticipated from the transcripts from the 621 + 1G-->T or 711 + 1G-->T alleles, respectively. The third product was apparently derived from an alternatively spliced mRNA species in the absence of the nominal splice site (in 621 + 1G-->T) through the use of a cryptic splice donor sequence (TT528/GTGAGG) within exon 4. Although reading frames appeared to be preserved in all three putative transcripts, significant portions of the presumed first and second transmembrane spans as well as the immediately following cytoplasmic domain would be deleted from the mutant CFTR polypeptides, if made. These observations are consistent with a loss of CFTR function in this cystic fibrosis patient.