Diabetes, Vol 40, Issue 6 777-782, Copyright © 1991 by American Diabetes Association
Detection of mutations in insulin-receptor gene in NIDDM patients by analysis of single-stranded conformation polymorphisms
S O'Rahilly, WH Choi, P Patel, RC Turner, JS Flier and DE Moller
Department of Medicine, Beth Israel Hospital, Boston, Massachusetts 02215.
We used the recently described technique of single-stranded
conformation-polymorphism (SSCP) analysis to examine the insulin-receptor
locus. First, the ability of the method to detect known mutations and
polymorphisms in the insulin-receptor coding sequence was assessed. Regions
of the insulin-receptor sequence containing 16 different nucleotide
changes, 9 in patient genomic DNA and 7 as cloned cDNA in plasmids, were
analyzed. All 9 patient genomic DNA mutants and 5 of 7 plasmid mutants
exhibited variant SSCP patterns. To investigate the potential of the
technique for screening many patients, the 5 exons that encode the tyrosine
kinase domain of the insulin receptor were examined in 30 unrelated white
subjects with non-insulin-dependent diabetes mellitus (NIDDM). Exons 17-21
were amplified from genomic DNA with polymerase chain reaction and
subjected to SSCP analysis. Exons 19, 20, and 21 revealed no bands of
aberrant migration, suggesting a high degree of conservation of these
sequences. One diabetic subject had an SSCP variant in exon 18. Direct
sequencing of this subject's genomic DNA revealed a heterozygous missense
mutation (Lys1068----Glu1068). Five different SSCP patterns were detected
in exon 17. Based on direct sequencing, these patterns were explained by
combinations of three different nucleotide substitutions, two of which were
common silent polymorphisms. One subject had a heterozygous missense
mutation Val985---- Met985. Allele-specific oligonucleotide hybridization
confirmed the presence of these mutations in the appropriate diabetic
subjects and also detected the Val985 mutation in heterozygous form in 1 of
13 nondiabetic white subjects. SSCP analysis is a sensitive rapid method
for screening for mutations in the insulin-receptor gene.(ABSTRACT
TRUNCATED AT 250 WORDS)