Methods & Technology

CTGT uses complementary methodologies to attain the most accurate mutation detection results available:

1. DNA Sequencing

Direct DNA sequencing of PCR products generated from genomic DNA is performed for all tests offered by Connective Tissue Gene Tests.  In all instances, sequencing of exons and exon-intron boundaries is performed for all genes. This is the gold standard for mutation detection in genes and is highly sensitive for point mutations, splice site mutations and small exonic deletions, insertions and indels.  Connective Tissue Gene Tests’ many years of experience with this approach combined with its extensive mutation and polymorphism databases ensure very high test sensitivity.

2. Deletion / Duplication Analysis

While extremely sensitive, direct DNA sequencing does not detect all types of mutations, including some deletions. Following extensive evaluation of the methodologies available for deletion detection, Connective Tissue Gene Tests has decided to employ two alternative approaches.

i.  A real-time PCR based test for FBN1 deletion / duplication detection is currently available.  The real-time PCR FBN1 assay is a sensitive, quantitative test designed to detect single exon or multi-exon deletions / duplications.  The test may also detect smaller deletions in exons depending upon the specific location of the deletion in question.

ii.  We are also in the final stages of testing a very high density hybridization array that we will offer in the near future.  This array is designed to detect copy number variations in most of the genes that we currently offer DNA sequencing for.

Connective Tissue Gene Tests remains actively involved in evaluating alternative methodologies for mutation detection.  These methodologies will be considered for introduction as they mature and are proven reliable, accurate and superior or complementary to existing technology.