Frequency of FRM1 premutations in a consecutive newborn Manitoba population of PCR of Guthrie blood spots
- Univ. of Manitoba, Winnipeg (Canada)
We have analyzed the frequency of premutations of the FRM1 gene in 3000 X chromosomes of 1000 male and 1000 female consecutive newborn Guthrie blood spots in an unlinked, anonymous survey. The CGG repeat sizes were calculated by measuring the length of products of the PCR reaction based on the molecular size of labeled markers in a denaturing sequencing gel assay. For consistent PCR amplification a DNA microextraction was necessary, including a phenol/chloroform series. In our population, the CGG repeat ranged from 9-106 but 96% of alleles had fewer than 40 repeats. The most frequent allele was a repeat of 28. Approximately 2.7% of alleles had CGG repeats ranging from 40-49 and 0.36% of alleles had repeats ranging from 50-59. The frequency of alleles {ge}60 repeats in the Manitoba population is approximately 0.18%. The use of Guthrie blood spots for population screening of fra(X) premutations is not recommended. The necessity of a phenol/chloroform DNA microextraction is tedious and time consuming. The low yield of DNA (-250 ng) does not allow for re-analysis by Southern blot of apparently homozygous females and may result in an underestimate of premutation carrier status.
- OSTI ID:
- 133890
- Report Number(s):
- CONF-941009-; ISSN 0002-9297; TRN: 95:005313-0624
- Journal Information:
- American Journal of Human Genetics, Vol. 55, Issue Suppl.3; Conference: 44. annual meeting of the American Society of Human Genetics, Montreal (Canada), 18-22 Oct 1994; Other Information: PBD: Sep 1994
- Country of Publication:
- United States
- Language:
- English
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