A new rare allele at the CGG repeat polymorphism in the first intron of human c-H-ras gene.
We have examined a region in the first intron of the human c-H-ras gene containing a CGG repeat. This region was previously shown to be variable in length. The length variation was attributed to the presence of the CGG repeat after estimation of its electrophoretic mobility. In the present report we have characterized in detail this region by PCR-RFLP and automated sequencing, in a total of 102 histologically normal tissues from unrelated individuals affected by lung and breast cancer. Four alleles were detected and analysis of their internal sequence showed that the length alterations of this region were due to the presence of 5, 6, 8 and 9 CGG triplets respectively. The last three occur most often (44.1%, 34.8%, 20.6% respectively) and coincide with three previously reported alleles (Riggins et al, Hum Mol Genet 9: 775, 1992). The fourth allele consisting of 5 repeats is a rare one (0.5%), whilst alleles with 7, and a previously reported one suggested to comprise 11 repeats (1%) were not present in our cohort. This polymorphism coincides in position with an element that was previously shown to possess regulatory activity.
Kotsinas
A
A
Department of Histology-Embryology, Medical School, University of Athens, Athens, Greece.
Gorgoulis
V G
VG
Zacharatos
P
P
Liloglou
T
T
Leonardou
P
P
Bramis
J
J
Troupis
T G
TG
Fotiadis
C
C
Field
J K
JK
Kittas
C
C
D000483:Alleles; D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics*; D005260:Female; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D007438:Introns / Q000235:genetics; D008175:Lung Neoplasms / Q000235:genetics*; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D018911:Trinucleotide Repeats