TY - JOUR
T1 - A rare branch-point mutation is associated with missplicing of fibrillin-2 in a large family with congenital contractural arachnodactyly
AU - Maslen, Cheryl
AU - Babcock, Darcie
AU - Raghunath, Michael
AU - Steinmann, Beat
N1 - Funding Information:
We are grateful to the family for their participation and collaboration. In particular, the authors acknowledge the Swiss Marfan Foundation for bringing this family to their attention. The authors also thank Dr. Robert Glanville for critical reading of the manuscript and for insightful discussion and comments and thank Cynthia Bohan for expert technical assistance. This study was supported by National Institute of Arthritis, Musculoskeletal and Skin Disease grant 5R29AR41846-03 to C.M., Swiss National Science Foundation grant 32-42198.94 to B.S., and Deutsche Forschungsge-meinschaft grants Ra 447/3-1 and Ra 447/3-2 to M.R.
PY - 1997/6
Y1 - 1997/6
N2 - Congenital contractural arachnodactyly (CCA) is an autosomal dominant disorder that is phenotypically similar to but genetically distinct from Marfan syndrome. Genetic-linkage analysis has implicated the fibrillin-2 gene (FBN2) as the CCA locus. Mutation analysis of two isolated CCA patients revealed missense mutations, indicating that defects in FBN2 may be responsible for this disorder. However, cosegregation of a mutant allele with the disease phenotype has not yet been established. We have investigated the primary cause of CCA in a large well-characterized kindred with five generations comprising 18 affected individuals. Previous studies demonstrated linkage of this family's CCA phenotype to FBN2. Mutation analysis of cDNA derived from the proband and her affected brother, using a nonisotopic RNase cleavage assay, revealed the partial skipping of exon 31. Approximately 25% mutant transcript is produced, which is apparently sufficient to cause a CCA phenotype. Sequence analysis of genomic DNA revealed an unusual base composition for intron 30 and identified the mutation, a g-26t transversion, in the vicinity of the splicing branch-point site in intron 30. Genomic DNA from 30 additional family members, both affected and unaffected, then was analyzed for the mutation. The results clearly demonstrate cosegregation of the branch-point mutation with the CCA phenotype. This is the first report of a CCA mutation in a multiplex family, unequivocally establishing that mutations in FBN2 are responsible for the CCA phenotype. In addition, branch- point mutations only very rarely have been associated with human disease, suggesting that the unusual composition of this intron influences splicing stability.
AB - Congenital contractural arachnodactyly (CCA) is an autosomal dominant disorder that is phenotypically similar to but genetically distinct from Marfan syndrome. Genetic-linkage analysis has implicated the fibrillin-2 gene (FBN2) as the CCA locus. Mutation analysis of two isolated CCA patients revealed missense mutations, indicating that defects in FBN2 may be responsible for this disorder. However, cosegregation of a mutant allele with the disease phenotype has not yet been established. We have investigated the primary cause of CCA in a large well-characterized kindred with five generations comprising 18 affected individuals. Previous studies demonstrated linkage of this family's CCA phenotype to FBN2. Mutation analysis of cDNA derived from the proband and her affected brother, using a nonisotopic RNase cleavage assay, revealed the partial skipping of exon 31. Approximately 25% mutant transcript is produced, which is apparently sufficient to cause a CCA phenotype. Sequence analysis of genomic DNA revealed an unusual base composition for intron 30 and identified the mutation, a g-26t transversion, in the vicinity of the splicing branch-point site in intron 30. Genomic DNA from 30 additional family members, both affected and unaffected, then was analyzed for the mutation. The results clearly demonstrate cosegregation of the branch-point mutation with the CCA phenotype. This is the first report of a CCA mutation in a multiplex family, unequivocally establishing that mutations in FBN2 are responsible for the CCA phenotype. In addition, branch- point mutations only very rarely have been associated with human disease, suggesting that the unusual composition of this intron influences splicing stability.
UR - http://www.scopus.com/inward/record.url?scp=0030971763&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030971763&partnerID=8YFLogxK
U2 - 10.1086/515472
DO - 10.1086/515472
M3 - Article
C2 - 9199560
AN - SCOPUS:0030971763
SN - 0002-9297
VL - 60
SP - 1389
EP - 1398
JO - American Journal of Human Genetics
JF - American Journal of Human Genetics
IS - 6
ER -