A significant fraction of hereditary nonpolyposis colorectal cancer cases with defective mismatch repair (ie, Lynch syndrome) have large genomic deletions or duplications in the mismatch repair genes, hMLH1 and hMSH2, which can be challenging to detect by traditional methods. For this study, we developed and validated a novel Southern blot analysis method that allows for ascertainment of the extent of the dosage alterations on an exon-by-exon basis and compared this method to a second novel technique, multiplex ligation-dependent probe amplification (MLPA). From a total of 254 patients referred for Lynch syndrome testing, 20 of the 118 MLH1 cases and 42 of the 136 MSH2 cases had large genomic alterations, as detected by Southern blot.
View Article and Find Full Text PDFBackground: Multiple endocrine neoplasia type 2 (MEN2) is a cancer syndrome with well-characterized causative mutations. Missense mutations in approximately 15 codons of the RET gene have been linked to disease phenotypes in the vast majority of cases. These missense mutations range from very simple single nucleotide base changes to more numerous changes at a given codon; they therefore are often tested for by more than one DNA-based diagnostic method.
View Article and Find Full Text PDFShort-chain acyl-CoA dehydrogenase (SCAD) deficiency is a clinically heterogeneous disorder. The clinical phenotype varies from fatal metabolic decompensation in early life to subtle adult onset, some patients remain asymptomatic. Two mutations (511C>T; 625G>A) have been described in exons 5 and 6 of the SCAD gene.
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