M. Pritchard
Boston Children's Hospital
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Publication
Featured researches published by M. Pritchard.
Science | 1991
Eric J. Kremer; M. Pritchard; Michael Lynch; Sui Yu; K. Holman; Elizabeth Baker; Stephen T. Warren; D Schlessinger; Grant R. Sutherland; Robert I. Richards
The sequence of a Pst I restriction fragment was determined that demonstrate instability in fragile X syndrome pedigrees. The region of instability was localized to a trinucleotide repeat p(CCG)n. The sequence flanking this repeat were identical in normal and affected individuals. The breakpoints in two somatic cell hybrids constructed to break at the fragile site also mapped to this repeat sequence. The repeat exhibits instability both when cloned in a nonhomologous host and after amplification by the polymerase chain reaction. These results suggest variation in the trinucleotide repeat copy number as the molecular basis for the instability and possibly the fragile site. This would account for the observed properties of this region in vivo and in vitro.
Science | 1991
Sui Yu; M. Pritchard; Eric J. Kremer; Michael Lynch; J Nancarrow; Elizabeth Baker; K. Holman; John C. Mulley; Stephen T. Warren; David Schlessinger
DNA sequences have been located at the fragile X site by in situ hybridization and by the mapping of breakpoints in two somatic cell hybrids that were constructed to break at the fragile site. These hybrids were found to have breakpoints in a common 5-kilobase Eco RI restriction fragment. When this fragment was used as a probe on the chromosomal DNA of normal and fragile X genotype individuals, alterations in the mobility of the sequences detected by the probe were found only in fragile X genotype DNA. These sequences were of an increased size in all fragile X individuals and varied within families, indicating that the region was unstable. This probe provides a means with which to analyze fragile X pedigrees and is a diagnostic reagent for the fragile X genotype.
Journal of Medical Genetics | 1991
Robert I. Richards; K. Holman; H Kozman; Eric J. Kremer; Michael Lynch; M. Pritchard; Sui Yu; John C. Mulley; G.R. Sutherland
We report the genetic localisation of the fragile site at Xq27.3 associated with fragile X syndrome. The position of the fragile site within the multipoint linkage map was determined using two polymorphic microsatellite AC repeat markers FRAXAC1 and FRAXAC2. These markers were physically located within 10 kilobases and on either side of the p(CCG)n repeat responsible for the fragile site. FRAXAC1 has five alleles with heterozygosity of 44% and is in strong linkage disequilibrium with FRAXAC2 which has eight alleles and a heterozygosity of 71%. No recombination was observed either between these markers in 40 normal CEPH pedigrees or with the fragile X in affected pedigrees. These markers provide the means for accurate diagnosis of the fragile X genotype in families by rapid polymerase chain reaction analysis and were used to position the fragile X within the multipoint map of the X chromosome to a position 3.7 cM distal to DXS297 and 1.2 cM proximal to DXS296.
The Lancet | 1991
G.R. Sutherland; Eric J. Kremer; Michael Lynch; M. Pritchard; Sui Yu; Robert I. Richards; Eric Haan
Fragile X syndrome, associated with the fragile X chromosome, is the most common cause of familial mental retardation. The condition is characterised by a heritable DNA sequence that consists of an abnormal number of CCG repeats, and which is unstable in both mitosis and meiosis. We suggest that such heritable unstable DNA sequences could be present in other parts of the genome and that these might explain a number of genetic events that are not well understood in terms of classic genetic mechanisms. Such poorly explained observations include anticipation, incomplete penetrance, variable expression, and possibly imprinting, variegation, and multifactorial inheritance.
Mammalian Genome | 1992
M. Pritchard; Elizabeth Baker; David F. Callen; Grant R. Sutherland; Andrew F. Wilks
A member of a new class of protein tyrosine kinases, JAK1, has been mapped to 1p31.3 by in situ hybridization and Southern blot analysis of a panel of mouse-human hybrid cell lines. A murine protein tyrosine kinase, related to, but distinct, from JAK1, was mapped by in situ hybridization to human Chromosome (Chr) 9p24 and 1p31.3.
American Journal of Human Genetics | 1992
Sui Yu; John C. Mulley; D. Loesch; Gillian Turner; Andrew Donnelly; Agi K. Gedeon; D. Hillen; Eric J. Kremer; Michael Lynch; M. Pritchard; G.R. Sutherland; Robert I. Richards
Nature | 1990
Nicholas M. Gough; David P. Gearing; Nicos A. Nicola; Elizabeth Baker; M. Pritchard; David F. Callen; Grant R. Sutherland
The New England Journal of Medicine | 1991
Grant R. Sutherland; Agi K. Gedeon; Louise Kornman; Andrew Donnelly; Roger W. Byard; John C. Mulley; Eric J. Kremer; Michael J. Lynch; M. Pritchard; Sui Yu; Robert I. Richards
American Journal of Human Genetics | 1991
Eric J. Kremer; Sui Yu; M. Pritchard; Ramaiah Nagaraja; D. Heitz; Michael Lynch; Elizabeth Baker; V. J. Hyland; R. D. Little; Morimasa Wada; Daniela Toniolo; A. Vincent; François Rousseau; David Schlessinger; G.R. Sutherland; Robert I. Richards
Archive | 1993
Grant R. Sutherland; Robert I. Richards; David Schlessinger; Ramaiah Nagaraja; Eric J. Kremer; Sui Yu; Elizabeth Baker; John C. Mulley; Jean-Louis Mandel; M. Pritchard; Michael J. Lynch