Figure 1.
Distribution of activation ratio.
Activation ratio was determined by Southern blot analysis. The distribution approximates a normal distribution with a mean of 0.54.
Table 1.
A comparison of age, CGG repeat size, and FMR1 mRNA levels in male and female premutation carriers.
Figure 2.
Scatterplot of FMR1 mRNA levels by total CGG length.
A linear regression model with model fit using CGG length as a continuous variable a) in premutation males and b) in premutation females. FMR1 mRNA levels show strong (P<0.001) correlation to total CGG length.
Figure 3.
Scatterplot of FMR1 mRNA levels by length of CGG pure stretch.
A linear regression model with model fit using CGG pure stretch as a continuous variable a) in premutation males and b) in premutation females. FMR1 mRNA levels appear strongly related to pure CGG stretch (P<0.001).
Figure 4.
A box plot of total CGG length for each number of AGG interruptions.
A) In premutation male data, significant difference in total CGG length of subjects with no AGG interruptions (130 subjects) and those with 1 or 2 interruptions (96 and 55 subjects respectively) was found (P<0.001 in both cases). No significance was found in total CGG length of subjects with 1 AGG interruption compared to 2 AGG interruptions (P = 0.935). B) Premutation female data showed significant difference in total CGG length of subjects with no AGG interruptions (259 subjects) and those with 1 or 2 interruptions (143 and 78 subjects respectively) (P<0.001) but no difference with remaining pairs.
Figure 5.
A box plot of FMR1 mRNA levels for each number of AGG interruptions.
No difference was found in FMR1 mRNA levels between any of the AGG interruption groups a) in males (P = 0.060) or b) females (P = 0.066).
Figure 6.
Scatterplot of FMR1 mRNA levels by total CGG length.
A linear regression model showed no significant difference in the slopes for 0, 1, or 2 AGG interruptions a) in males (P>0.046) or b) females (P>0.448). See also Table 2.
Table 2.
Comparison of linear regression fits for FMR1 mRNA levels by total CGG length.
Figure 7.
Scatterplot of FMR1 mRNA levels by age.
A linear regression model showed no significant relationship between FMR1 mRNA levels and age, controlling for CGG length, in a) males (P = 0.093) or b) females (P = 0.297).
Figure 8.
Electropherogram of FMR1 CGG linker PCR.
a) PCR product from a premutation female with 1 normal allele (Allele 1) with 30 CGG repeats and 1 premutation allele (Allele 2) with 55 CGG repeats. Using a CCG chimeric primer, AGG interruptions can be identified as loss of signal intensity spanning 5 CGG peaks, followed by restoration of signal intensity. AGG interruptions occurring in the normal allele have a loss of approximately half the CGG peak intensity due to the presence of CGG peaks from the premutation allele. Allele 1: (CGG)10-AGG-(CGG)9-AGG-(CGG)9; Allele 2: (CGG)9-AGG-(CGG)9-AGG-(CGG)35. b) PCR product using a GGC chimeric primer and the same DNA sample as Fig. 8a. AGG interruptions result in loss of signal in 4 consecutive CGG peaks, followed by restoration in signal. Overlapping AGG interruptions results in peak intensity falling to baseline levels.