Author
S. Youngman
Other affiliations: Lincoln's Inn
Bio: S. Youngman is an academic researcher from University of Wales. The author has contributed to research in topics: Genetic linkage & Huntington's disease. The author has an hindex of 14, co-authored 16 publications receiving 14279 citations. Previous affiliations of S. Youngman include Lincoln's Inn.
Papers
More filters
TL;DR: In this article, the authors used haplotype analysis of linkage disequilibrium to spotlight a small segment of 4p16.3 as the likely location of the defect, which is expanded and unstable on HD chromosomes.
7,224 citations
Journal Article•
TL;DR: The Huntington's disease mutation involves an unstable DNA segment, similar to those described in fragile X syndrome, spino-bulbar muscular atrophy, and myotonic dystrophy, acting in the context of a novel 4p16.3 gene to produce a dominant phenotype.
6,992 citations
TL;DR: A fine-structure genetic map is produced that establishes the relative order of the clusters and further narrows the target area containing the HD gene.
78 citations
TL;DR: 55 couples where one partner was at 50% risk of Huntington's disease were investigated with a DNA probe closely linked to HD, with a view to exclusion testing in a future pregnancy, in 3 of 9 pregnancies so far.
72 citations
Journal Article•
TL;DR: The proximal gap is closed, the maximum size of which can now be placed accurately at 2.5 Mb, and the proximal boundary for the HD candidate region centromeric is moved to the gap within a "hot spot" for recombination between D 4S10 and D4S125.
Abstract: The Huntington disease (HD) gene has been mapped 4 cM distal to D4S10 within the telomeric chromosome band, 4p16.3. The published physical map of this region extends from D4S10 to the telomere but contains two gaps of unknown size. Recombination events have been used to position the HD mutation with respect to genetic markers within this region, and one such event places the gene proximal to D4S168, excluding the distal gap as a possible location for the defect. One previously published recombination event appeared to have excluded the proximal gap. We have reassessed this event and have moved the proximal boundary for the HD candidate region centromeric to the gap within a "hot spot" for recombination between D4S10 and D4S125. We have closed the proximal gap and report here the complete physical map spanning the HD candidate region from D4S10 to D4S168, the maximum size of which can now be placed accurately at 2.5 Mb.
69 citations
Cited by
More filters
TL;DR: In this article, the authors used haplotype analysis of linkage disequilibrium to spotlight a small segment of 4p16.3 as the likely location of the defect, which is expanded and unstable on HD chromosomes.
7,224 citations
Journal Article•
TL;DR: The Huntington's disease mutation involves an unstable DNA segment, similar to those described in fragile X syndrome, spino-bulbar muscular atrophy, and myotonic dystrophy, acting in the context of a novel 4p16.3 gene to produce a dominant phenotype.
6,992 citations
TL;DR: A new algorithm for finding tandem repeats which works without the need to specify either the pattern or pattern size is presented and its ability to detect tandem repeats that have undergone extensive mutational change is demonstrated.
Abstract: A tandem repeat in DNA is two or more contiguous, approximate copies of a pattern of nucleotides. Tandem repeats have been shown to cause human disease, may play a variety of regulatory and evolutionary roles and are important laboratory and analytic tools. Extensive knowledge about pattern size, copy number, mutational history, etc. for tandem repeats has been limited by the inability to easily detect them in genomic sequence data. In this paper, we present a new algorithm for finding tandem repeats which works without the need to specify either the pattern or pattern size. We model tandem repeats by percent identity and frequency of indels between adjacent pattern copies and use statistically based recognition criteria. We demonstrate the algorithm’s speed and its ability to detect tandem repeats that have undergone extensive mutational change by analyzing four sequences: the human frataxin gene, the human β T cell receptor locus sequence and two yeast chromosomes. These sequences range in size from 3 kb up to 700 kb. A World Wide Web server interface at c3.biomath.mssm.edu/trf.html has been established for automated use of the program.
6,577 citations
TL;DR: Findings in other neurodegenerative diseases indicate that a broadly similar process of neuronal dysfunction is induced by diffusible oligomers of misfolded proteins.
Abstract: The distinct protein aggregates that are found in Alzheimer's, Parkinson's, Huntington's and prion diseases seem to cause these disorders. Small intermediates - soluble oligomers - in the aggregation process can confer synaptic dysfunction, whereas large, insoluble deposits might function as reservoirs of the bioactive oligomers. These emerging concepts are exemplified by Alzheimer's disease, in which amyloid beta-protein oligomers adversely affect synaptic structure and plasticity. Findings in other neurodegenerative diseases indicate that a broadly similar process of neuronal dysfunction is induced by diffusible oligomers of misfolded proteins.
4,499 citations
TL;DR: A minimal cosegregating region containing the AD3 gene is defined, and at least 19 different transcripts encoded within this region corresponds to a novel gene whose product is predicted to contain multiple transmembrane domains and resembles an integral membrane protein.
Abstract: Some cases of Alzheimer's disease are inherited as an autosomal dominant trait. Genetic linkage studies have mapped a locus (AD3) associated with susceptibility to a very aggressive form of Alzheimer's disease to chromosome 14q24.3. We have defined a minimal cosegregating region containing the AD3 gene, and isolated at least 19 different transcripts encoded within this region. One of these transcripts (S182) corresponds to a novel gene whose product is predicted to contain multiple transmembrane domains and resembles an integral membrane protein. Five different missense mutations have been found that cosegregate with early-onset familial Alzheimer's disease. Because these changes occurred in conserved domains of this gene, and are not present in normal controls, they are likely to be causative of AD3.
4,110 citations