Abstract
Purpose: We have developed sensitive diagnostic procedures for studies on the normal and mutant alleles of the triplet repeat genes associated with myotonic dystrophy and fragile X in single human somatic cells, gametes and embryos.
Methods: Polymerase chain reaction (PCR) assays for the normal alleles of the myotonic dystrophy and fragile X loci have been refined to the sensitivity of the single cell. In addition, we have developed a simple PCR-based technique, termed ‘Repeat Primer PCR’, which can detect the full fragile X expansion in small samples of buccal cells.
Conclusions: The assay for the triplet repeat sequence in the myotonic dystrophy locus could not be used to study stability since we observed additional PCR products derived fromin vitro expansion of the triplet repeat sequence during the PCR reaction itself. The implications ofin vitro expansion and allele drop-out for studies on the timing of the expansion in development and preimplantation diagnosis of triplet repeat diseases are discussed. The development of a new PCR procedure to identify the expanded alleles of the fragile X locus could prove invaluable for monitoring the timing of repeat expansion in early embryonic development. Triplet repeat polymorphisms provide a means of identifying the maternally and paternally-derived alleles of the myotonic dystrophy gene. Using single cell reverse transcriptase PCR analysis, we have monitored the onset of the myotonic dystrophy gene transcription in early preimplantation embryos. Transcripts from the paternally- inherited allele of the myotonic dystrophy gene are already detectable in the 1-cell stage human embryo.
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References
Fu Y-H, Kuhl D, Pizzuti A, Pieretti M, Sutcliffe J, Richards S, Verkerk A,et al. Variation of the CCG repeat at the fragile X site results in genetic instability: resolution of the Sherman paradox. Cell 1991;67:1047–1058
Kremer E, Prichard M, Lynch M, Yu S, Holman K, Baker E,et al. Mapping of DNA instability at the fragile X to a trinucleotide repeat sequence p(CCG)n. Science 1991;252:1711–1714
Oberle I, Rousseau F, Hietz D, Kretz C, Devys D, Hanauer A,et al. Instability of a 550-base pair DNA segment and abnormal methylation in fragile X syndrome. Science 1991;252:1097–1102
Verkerk A, Pieretti M, Sutcliffe J, Fu Y, Kuhl D, Pizzuti A,et al. Identification of a gene (FMR-1) containing a CGG repeat coincident with a breakpoint cluster region exhibiting length variation in fragile X syndrome. Cell 1991;65:904–914
Yu S, Pritchard M, Kremer E, Lynch M, Nancarrow J, Baker E,et al. Fragile X genotype characterised by an unstable region of DNA. Science 1991;252:1179–1181
Brook JD, McCurrah ME, Harley HG,et al. Molecular basis of myotonic dystrophy: expansion of a trinucleotide (CTG) repeat at the 3′ end of a transcript encoding a protein kinase family member. Cell 1992;68:799–808
Fu Y-H, Pizzuti A, Fenwick R Jr, King J, Rajnarayan S, Dunne P,et al. An unstable triplet repeat in a gene related to myotonic muscular dystrophy. Science 1992;255:1256–1258
Lavedan C, Hofmann-Radvanyi H, Shelbourne P, Rabes JP, Duros C, Savoy D,et al. Myotonic dystrophy: Size- and sex-dependent dynamics of CTG meiotic instability and somatic mocaisism. Am J Hum Genet 1993;52:875–883
Mahadevan M, Tsilfidis C, Sabourin L, Shutler G, Amemiya C, Jansen GM,et al. Myotonic dystrophy mutation: An unstable CTG repeat in the 3′ untranslated region of the gene. Science 1992;255:1253–1255
Bates G, Lehrach H: Trinucleotide repeat expansions and human genetic disease. BioEssays 1994;16:277–284
Pierretti M, Zhang F, Fu Y, Warren S, Oostra B, Caskey C, Nelson D: Absence of expression of the FMR-1 gene in fragile X syndrome. Cell 1991;66:817–822
Hansen R, Gartler S, Scott C, Chen S, Laird C: Methylation analysis of CGG sites in the CpG island of the human FMR-1 gene. Hum Mol Genet 1992;1:571–578
Devys D, Biancalana V, Rousseau F, Boue J, Mandel J, Oberle I: Analysis of full fragile X mutations in fetal tissues and monozygotic twins indicate that abnormal methylation and somatic heterogeneity are established early in development. Am J Med Genet 1992;43:208–216
Rousseau F, Heitz D, Biancalana V, Blumenfeld S, Kretz C, Boue Jet al. Direct diagnosis by DNA analysis of the fragile X syndrome of mental retardation. New Eng J Med 1991;325:1673–1681
Wohrle D, Hennig I, Vogel W, Steinbach P: Mitotic stability of fragile X mutations in differentiated cells indicates early post-conceptual trinucleotide repeat expansion. Nat Genet 1993;4:140–142
Reyniers E, Vits L, De Boulle K, Van Roy B,et al. The full mutation in the FMR-1 of male fragile X patients is absent in their sperm. Nat Genet 1993;4:143–146
Bachner D, Steinbach P, Wohrle D, Just W, Heamister H: Enhanced FMR-1 expression in testis. Nat Genet 1993;4:115–116
Jansen G, Willems P, Coerwinkel M, Nillsen W, Smeets H, Vits L,et al. Gonosomal mosaicism in myotonic dystrophy patients: involvement of miotic events in (CTG)n repeat variation and selection against extreme expansion in sperm. Am J Hum Genet 1994;54:575–585
Williams C, Davies D, Williamson R: Segregation of (Delta)F508 and normal CFTR alleles in human sperm. Hum Mol Genet 1993;2:445–448
Kontogianni E, Davies E, Carey N, Johnson K, Monk M: Slippage and base misincorporationin vitro during PCR of the myotonic dystrophy locus in single cells (in preparation)
Brunner HG, Nillsen W, van Oost BA, Jansen G, Wieringa B, Ropers H-H, Smeets, HJM: Presymptomatic diagnosis of myotonic dystrophy. J Med Genet 1992;29:780–784
Zhang L, Leeflang EP, Yu J, Arnheim N: Studying human mutations by sperm typing: instability of CAG trinucleotide repeats in the human androgen receptor gene. Nat Genet 1993;7:531–535
Pergolizzi RG, Erster SH, Goonewardena P, Brown WT: Detection of full fragile X mutation. Lancet 1992;339:271–272
Brown WT, Houck GE, Jezioroska A, Levinson FN,et al. Rapid fragile X carrier screening and parental diagnosis using a non-radioactive PCR test. JAMA 1993;270:1569–1575
Warren ST, Nelson DL: Advances in molecular analysis of fragile X syndrome. JAMA 1994;271:536–542
Frohman MA: Rapid amplification of complimentary DNA ends for generation of full-length complimentary DNAs: Thermal RACE. Methods Enzymol 1993;218:340–356
Daniels R, Kinis T, Serhal P, Monk M: Expression of the myotonin protein kinase gene in preimplantation human embryos. Hum Mol Genet 1995;4:389–393
Chong SS, Eichler EE, Nelson DL, Hughes MR: Robust amplification and ethidium-visible detection of the fragile X syndrome CGG repeat using Pfu polymerase. Am J Med Gen 1994;51:522–526
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Daniels, R., Holding, C., Kontogianni, E. et al. Single-cell analysis of unstable genes. J Assist Reprod Genet 13, 163–169 (1996). https://doi.org/10.1007/BF02072539
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DOI: https://doi.org/10.1007/BF02072539