TY - JOUR
T1 - APC germline mutations in individuals being evaluated for familial adenomatous polyposis
T2 - A review of the mayo clinic experience with 1591 consecutive tests
AU - Kerr, Sarah E.
AU - Thomas, Cheryl B.
AU - Thibodeau, Stephen N.
AU - Ferber, Matthew J.
AU - Halling, Kevin C.
PY - 2013
Y1 - 2013
N2 - Inactivating APC mutations cause familial adenomatous polyposis, classically characterized by hundreds to thousands of adenomatous colorectal polyps and cancer. Historically, 98% of pathogenic alterations in APC are nonsense or frameshift mutations; however, few reported series have used techniques that test for large deletions or duplications. Splice site mutations are only rarely documented. Consecutive cases (n = 1591) submitted for complete APC gene analysis during a 4-year period were reviewed. Testing included mutation screening (Sanger sequencing or conformation sensitive gel electrophoresis and protein truncation testing) with reflex confirmation sequencing. Gene deletion or duplication analysis was performed in 1421 cases by multiplex ligation-dependent probe amplification. Testing yielded 411 pathogenic, 20 likely pathogenic, 15 variant of uncertain significance, 140 likely benign, and 1005 negative reports. Identified were 168 novel variants (103 pathogenic, 5 likely pathogenic, 12 variant of uncertain significance, and 48 likely benign). Of the 431 pathogenic or likely pathogenic mutations, frameshift, nonsense, splice site, and large deletion or duplication mutations represented 43%, 42%, 9%, and 6% of cases, respectively. This is the largest report of clinical APC testing experience with concurrent multiplex ligation-dependent probe amplification. In addition to nonsense and frameshift mutations, large deletions or duplications and canonical splice site mutations are a significant cause of familial adenomatous polyposis. Despite technological advances, broad allelic, locus, and phenotypic heterogeneity continue to pose challenges for genetic testing of patients with colorectal adenomatous polyposis.
AB - Inactivating APC mutations cause familial adenomatous polyposis, classically characterized by hundreds to thousands of adenomatous colorectal polyps and cancer. Historically, 98% of pathogenic alterations in APC are nonsense or frameshift mutations; however, few reported series have used techniques that test for large deletions or duplications. Splice site mutations are only rarely documented. Consecutive cases (n = 1591) submitted for complete APC gene analysis during a 4-year period were reviewed. Testing included mutation screening (Sanger sequencing or conformation sensitive gel electrophoresis and protein truncation testing) with reflex confirmation sequencing. Gene deletion or duplication analysis was performed in 1421 cases by multiplex ligation-dependent probe amplification. Testing yielded 411 pathogenic, 20 likely pathogenic, 15 variant of uncertain significance, 140 likely benign, and 1005 negative reports. Identified were 168 novel variants (103 pathogenic, 5 likely pathogenic, 12 variant of uncertain significance, and 48 likely benign). Of the 431 pathogenic or likely pathogenic mutations, frameshift, nonsense, splice site, and large deletion or duplication mutations represented 43%, 42%, 9%, and 6% of cases, respectively. This is the largest report of clinical APC testing experience with concurrent multiplex ligation-dependent probe amplification. In addition to nonsense and frameshift mutations, large deletions or duplications and canonical splice site mutations are a significant cause of familial adenomatous polyposis. Despite technological advances, broad allelic, locus, and phenotypic heterogeneity continue to pose challenges for genetic testing of patients with colorectal adenomatous polyposis.
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U2 - 10.1016/j.jmoldx.2012.07.005
DO - 10.1016/j.jmoldx.2012.07.005
M3 - Article
C2 - 23159591
AN - SCOPUS:84875443082
SN - 1525-1578
VL - 15
SP - 31
EP - 43
JO - Journal of Molecular Diagnostics
JF - Journal of Molecular Diagnostics
IS - 1
ER -