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W Y Hung

Publications and source records attributed to W Y Hung.

At least 73 records · Page 4Linked to original sources
PubMed1988

Genetic linkage studies in Alzheimer's disease families.

Alzheimer's disease is a devastating neurological disorder and the leading cause of dementia among the elderly. Recent studies have localized the gene for familial Alzheimer's disease to chromosome 21 in a series of early onset AD families (mean age of onset less than 60). Familial late onset AD (mean age of onset greater than 60) is a more common clinical form of the disorder. Thirteen families with multiply affected Alzheimer's disease family members were identified and sampled. Ten of these families were of the late onset Alzheimer's disease type. Simulation studies were used to evaluate the usefulness of these pedigrees in linkage studies in familial Alzheimer's disease. Linkage studies undertaken to test the localization of both early onset and late onset Alzheimer's disease families to chromosome 21 failed to establish linkage and excluded linkage from a large portion of the region where the early onset Alzheimer's disease gene was localized. These findings suggest that more than one etiology may exist for familial Alzheimer's disease and indicate the need for continued screening of the genome in familial Alzheimer's disease families.

Alzheimer Disease↗
PubMed1988

The poliovirus sensitivity (PVS) gene is on chromosome 19q12----q13.2.

Sensitivity to nonmodified poliovirus infection is an autosomal dominant trait, specific to primates. The gene for poliovirus sensitivity (PVS) is encoded on human chromosome 19. In order to sublocalize the PVS gene, we infected rodent-human hybrid cell lines that divide human chromosome 19 into four regions with poliovirus 1 and/or 3. When infected, these hybrid cell lines showed the typical cytopathic effect of poliovirus infection only if they contained 19q12----q13.2 as the smallest region of overlap. Appropriate negative and positive controls were used. PVS may be of relevance to myotonic dystrophy (DM) and the inherited motor neuron diseases: to DM because it localizes to the same region of chromosome 19 and to the inherited motor neuron diseases because it encodes a cell-surface receptor expressed on motor neurons.

Cell Line↗
PubMed1988

Duchenne muscular dystrophy: high frequency of deletions.

DNA probes are available for Duchenne muscular dystrophy (DMD) carrier detection and prenatal diagnosis. With probes for about 25% of the proximal portion of the gene, we found the proximal probes detected deletions in 23% of nonselected DMD boys, while a single distal probe detected 17% more as deletions. The combined percentage was 39% for all probes tested. Prenatal diagnosis and carrier detection are more accurate if deletions are mapped rather than by use of restriction fragment length polymorphism analysis. The effort involved in screening all affected boys for deletions is considerably less, and provides an accurate genetic marker for subsequent prenatal diagnosis in the family and prospective counseling for female relatives. It seems likely that, once the entire gene (cDNA) is available for screening, most DMD boys will show deletions.

Child↗
PubMed1988

Systematic gene mapping in man: data management considerations.

The application of recombinant DNA technology to linkage analysis is revolutionizing the gene mapping field through the availability of an increasing number of restriction fragment length polymorphisms (RFLP). The successful mapping of the human genome will lead to a new era of research in human genetics with implications for carrier detection and prenatal diagnosis in any number of disorders. In addition, the development of RFLP tightly linked to a disease is critical for the potential identification of the genetic defect. A systematic approach to human gene mapping whereby it is possible to simultaneously screen several disorders for linkage is discussed. Guidelines for the database management, field studies, DNA and lymphoblast cell transformation, family history and laboratory data are included. This methodology represents the integration and application of statistical and molecular genetic, clinical and tissue culture expertise to human gene mapping.

Chromosome Aberrations↗
PubMed1988

Update on the molecular genetics of Duchenne muscular dystrophy.

Three separate lines of evidence led to the assignment of the Duchenne muscular dystrophy (DMD) gene to the 21.2 band on the short arm of the X chromosome. A portion of the putative gene, thought to extend over 1-2 million base pairs has been recently cloned. DNA probes from the Xp21.2 region detect large deletions in 5-20% DMD boys and are presumed to lead to the DMD phenotype in those individuals. Deletions have also been noted in the DNA of patients with Becker muscular dystrophy. These exciting developments have a direct bearing on carrier detection and prenatal diagnosis. Prenatal diagnosis in deletion families approaches greater than 99% accuracy and can be utilized to save 50% of normal male fetuses carried by carrier mothers who would otherwise choose to abort all male fetuses.

Cloning, Molecular↗
PubMed1987

A new probe for the diagnosis of myotonic muscular dystrophy.

Myotonic muscular dystrophy (DM) is the most common muscular dystrophy, affecting adults as well as children. It is inherited as an autosomal dominant trait and is characterized by variable expressivity and late age-of-onset. Linkage studies have established the locus on chromosome 19. In order to identify tightly linked probes for diagnosis as well as to define in detail the DM gene region, chromosome 19 libraries were constructed and screened for restriction fragment length polymorphisms tightly linked to DM. A genomic clone, LDR152 (D19S19), was isolated that is tightly linked to DM; recombination fraction = 0.0 (95% confidence limits 0.0-0.03); lod score, 15.4.

Adult↗
PubMed1987

Genetic linkage studies of chromosome 17 RFLPs in von Recklinghausen neurofibromatosis (NF1).

Recent localization of the gene for von Recklinghausen neurofibromatosis (NF1) to chromosome 17 has led to studies to identify additional tightly linked probes that can be used in defining the primary genetic defect in NF1. We have examined and obtained blood for DNA linkage studies on over 250 individuals from 10 multigeneration neurofibromatosis families. We have analyzed 130 members in 7 families with the available chromosome 17 NF1 linked probes, pE51, D17S71, and D17Z1, as well as two probes generated from our own chromosome 17/19 enriched library (LDR92, LDR152A). Tight linkage was found between NF1 and the centromeric probe D17Z1 (theta = 0.04) and between NF1 and D17S71 (theta = 0.08). A definite recombinant was seen for the D17Z1 marker, which previously had not exhibited crossingover. Chromosome 17 DNA markers pE51, LDR92, and LDR152A gave slightly positive scores, which were not statistically significant.

Chromosomes, Human, Pair 17↗
PubMed1987

Linkage studies in peripheral neurofibromatosis.

Peripheral neurofibromatosis (NF) is one of the most common major genetic disorders in man. Its chromosomal location is unknown and questions regarding such factors as genetic heterogeneity remain unanswered. We have ascertained and sampled several large multi-generation families for linkage studies including one family of 66 subjects, 28 of whom were affected with NF. Recombinant DNA studies of several restriction fragment length polymorphisms (RFLPs) including C3, ApoC2, pBam34 (D19S6], HAUP[APRT], pE40-1 [D11521], Hp[Hp2 alpha], LDR92, and LDR111 failed to show a significant linkage (Z [lod score] greater than or equal to 3.00) in this family. In addition, the results excluded areas of the genome around the marker loci (Z greater than or equal to - 2.00) as potential sites for linkage. The maximum Z obtained with the markers was for Hp at theta (maximum recombination fraction) = 0.20 and Z = 0.399. We are now in the process of screening additional RFLPs and families for linkage to NF.

Genetic Linkage↗
PubMed1987

Familial inheritance of a DXS164 deletion mutation from a heterozygous female.

Restriction-fragment-length-polymorphism analysis was used to examine a female who is segregating for Duchenne muscular dystrophy (DMD) and a deletion of the DXS164 region of the X chromosome. The segregating female has no prior family history of DMD, and she has two copies of the DXS164 region in her peripheral blood lymphocytes. The following two hypotheses are proposed to explain the coincidence of the DMD phenotype and deletion of the DXS164 region in her offspring: (1) she may be a gonadal mosaic for cells with two normal X chromosomes and cells with one normal X chromosome and an X chromosome with a deletion of the DXS164 region; and (2) she may carry a familial X;autosome translocation in which the DXS164 region is deleted from one X chromosome and translocated to an autosome. The segregation of DMD and the DXS164 deletion in this family illustrates the importance of extended pedigree analysis when DXS164 deletions are used to identify female carriers of the DMD gene.

Chromosome Deletion↗
PubMed1986

Tight linkage of apolipoprotein C2 to myotonic dystrophy on chromosome 19.

The cDNA and genomic probes for apolipoprotein C2 detect two restriction fragment length polymorphisms on chromosome 19. The combined estimated percentage of heterozygosity, assuming equilibrium, is approximately 75%, ie, apolipoprotein C2 is informative in 75% of matings. We have analyzed over 350 individuals in large multigenerational families for linkage of apolipoprotein C2 to myotonic muscular dystrophy. The maximum lod score was 16.29 with the maximum recombination fraction (theta) of 0.02, with 95% confidence limits for theta of 0.001 to 0.065. Thus, apolipoprotein C2 is useful in carrier detection and prenatal diagnosis with an accuracy of about 98%.

Apolipoproteins↗
PubMed1981

Differential labelling of UDP-N-acetylglucosamine in Huntington's-chorea fibroblasts.

The hypothesis that there is impaired endogenous synthesis of glucosamine 6-phosphate in Huntington's-chorea fibroblasts was tested by double labelling matched pairs of fibroblasts in culture with carrier-free H3 32PO4 and [U-14C]glucosamine. The [32P]UDP-N-acetyl[14C]glucosamine and [14C]glucosamine 6-[32P]phosphate of the cellular soluble fraction was isolated by charcoal column and paper chromatography. There is no quantitative difference in 32P but a significant difference in 14C in these two sugars in a ratio of approx. 1.5 for Huntington's-chorea fibroblasts compared with normal fibroblasts.

Carbon Radioisotopes↗
PubMed1980

Huntington's-chorea fibroblasts. Cellular protein glycosylation.

Five cell cultures of Huntington's-chorea fibroblasts exhibit greater than normal protein and lipid glycosylation when labelled with [U-14C]glucosamine. Oligosaccharide--polypeptide chains from all molecular-weight ranges are labelled differentially on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. This difference in protein glycosylation is not accompanied by any apparent difference in general cellular protein synthesis or by a differential rate of glucosamine uptake or decreased degradation of [14C]glycosylated macromolecules. Additionally [U-14C]glucosamine exclusively labels hexosamines and sialic acid of cellular macromolecules.

Adult↗