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Biomedical subjects

M E Hodes

Publications and source records attributed to M E Hodes.

At least 55 records · Page 3Linked to original sources
PubMed1995

Genetic heterogeneity of autosomal recessive limb-girdle muscular dystrophy in a genetic isolate (Amish) and evidence for a new locus.

Limb-girdle muscular dystrophy (LGMD) is a hereditary myopathy presenting clinical and genetic heterogeneity. In 1991, a recessive form (LGMD2A) was linked to chromosome 15q in a genetic isolate from the Isle of La Réunion. Confirmation of this localization was subsequently reported in Brazilian and northern Indiana Amish pedigrees. Here we report the exclusion of the LGMD2A locus in six Amish kindreds from southern Indiana that are related by multiple consanguineous links to the same northern Indiana families in which the involvement of the chromosome 15 locus was previously demonstrated. These findings indicate unexpected genetic heterogeneity of LGMD in an Indiana Amish isolate. Furthermore, genetic analyses also ruled out the possible involvement of the chromosome 2 locus recently described (LGMD2B), thus demonstrating that a mutation within at least one additional locus leads to this condition. Several candidate genes putatively involved in neuromuscular disorders were also excluded.

Chromosomes, Human, Pair 15↗
PubMed1994

cDNA approaches to isolation of the mouse mutant weaver gene.

The mouse autosomal recessive mutant gene weaver (wv) results in abnormalities in cerebellum, substantia nigra and testis. Although a substracted cDNA library prepared by removing P31 (wv/wv) sequences from a P1 (wv/+) library should contain mainly nonrepetitive neonatal sequences, unfortunately, repetitive sequences still appear during screening. Two clones, one repetitive, the other not, are used to illustrate the problems encountered in attempting to isolate the weaver gene from a substrated cDNA library.

Amino Acid Sequence↗
PubMed1994

Analysis of region-specific library constructed by sequence-independent amplification of microdissected fragments surrounding weaver (wv) gene on mouse chromosome 16.

The C3-C4 region of mouse chromosome 16 was microdissected and amplified directly by sequence-independent amplification (SIA). The SIA product was proved to originate from the microdissected region by fluorescence in situ hybridization (FISH) and was cloned into the PCR II vector (mean insert size 506 bp). Colony hybridization showed that about 59% of the clones contained either unique or low copy number sequences. Southern blot analysis of 100 unique clones demonstrated that 50 clones hybridized with single (33 clones) or multiple (17 clones) bands on blots of DNA from a hamster-mouse hybrid cell line that contains mouse chromosome 16, 13 clones hybridized with mouse but not with the hamster-mouse hybrid DNA, 19 clones contained repetitive sequences, and the remaining 18 clones failed to yield bands. One third of the 100 unique clones hybridized to human genomic DNA. Thirty-three clones were sequenced. None of them was found in GenBank. Our results demonstrate that this relatively simple method of microdissection and cloning can produce a library of good quality.

Animals↗
PubMed1994

Novel cDNA clones obtained by antibody screening of a mouse cerebellar cDNA expression library.

In order to obtain cDNAs of genes that are expressed in cerebellar granule cells (GC), an antiserum was raised against GC isolated from mouse cerebella. Western blot analysis demonstrated that antibodies against multiple proteins were present and immunohistochemical analysis showed that at least some of these proteins were localized to cerebellar GC. The antiserum was used to screen an expression library derived from mouse cerebellar cDNA. Twenty-two granule cell antibody-positive (GCAP) clones were obtained. Of these, eight represented genes previously described and 14 were novel clones (not found in the GenBank database). In situ hybridization histochemistry showed that eight of the novel clones had moderate to strong expression in cerebellar GC and some of these clones were expressed also in the hippocampal formation. One such clone, GCAP-7, appears to represent a single-copy gene and the entire cDNA insert (2,688 bp) has been sequenced. The clone appears to consist primarily of the 3' untranslated portion, including a poly(A) tail and polyadenylation signals, of a 5 kb transcript. The GCAP clones should be useful for future studies of molecular biology of GC in normal individuals and in inherited neurologic disease with GC degeneration.

Amino Acid Sequence↗
PubMed1994

Molecular characterization of a novel cDNA from murine cerebellum, developmental expression, and distribution in brain.

Several novel cDNA clones were previously identified by immunoscreening a cerebellar cDNA expression library derived from heterozygous weaver (wu/+) mice at postnatal day one (P1) with an antigranule cell antiserum. One cDNA, GCAP-8 (granule cell antiserum-positive clone 8) has been further characterized. The 1.1 kb insert is a partial cDNA containing a segment near the 3' end of the full-length cDNA. The 5' end of the GCAP-8 cDNA contains a 259 nucleotide open reading frame (ORF) coding for the last 85 amino acids of the carboxy terminus of the encoded protein. The encoded polypeptide contains two highly hydrophobic segments interrupted by a basic stretch. The carboxy terminus of this protein is cysteine-rich, with 10 cysteine residues among the 85 amino acids. The GCAP-8 cDNA probably represents a single-copy gene. The GCAP-8 gene, designated Gcap1, was mapped to the distal region of mouse chromosome 5 by the analyses of two multilocus crosses. The distribution of the GCAP-8 mRNA in mouse brain was studied by in situ hybridization histochemistry. In the adult mouse brain, strong hybridization was detected in cerebellum, hippocampus, substantia nigra (SN), and cerebral cortex. In mouse cerebellum, hybridization was detected in granule cells, Purkinje cells, and in cells of the deep cerebellar nuclei (DCN). In human cerebellum, hybridization was detected in the granule cell layer. In the mouse, GCAP-8 is expressed at least as early as embryonic day 14 (E14) in the central nervous system (CNS).

Amino Acid Sequence↗
PubMed1993

Cellular distribution of the RNA transcripts of a newly discovered gene in the brain of normal, weaver, Purkinje cell degeneration and reeler mutant mice as evidenced by in situ hybridization histochemistry.

After we identified several novel cDNAs by screening a neonatal (P1) heterozygous weaver (wv/+) cerebellar cDNA expression library with a rabbit anti-mouse granule cell antiserum, we characterized and sequenced one cDNA, GCAP-8 (standing for granule cell antiserum positive, clone number 8). In this study we examined its expression and cellular distribution in adult cerebellar mutant mice as evidenced by in situ hybridization histochemistry. In wild-type (+/+) brain, strong hybridization signal is seen in cerebellum, hippocampus, substantia nigra (SN), and cerebral cortex; in the cerebellum, hybridization signal is seen in granule cells, Purkinje cells, and in cells of the deep cerebellar nuclei. In the granuloprival weaver (wv/wv) cerebellum, hybridization signal is seen mainly in Purkinje cells. GCAP-8 expression is reduced in wv/wv SN pars compacta, which is known to lose dopamine (DA) neurons. In Purkinje cell degeneration (pcd/pcd) mutants, granule cells show hybridization signal, but overall expression is decreased owing to the absence of Purkinje cells. In reeler (rl/rl) cerebellum, the strongest hybridization signal is found in a thin granule cell layer without the typical foliation pattern, while grain clusters representing ectopic Purkinje cells are observed in the subcortical white matter and the area of the deep cerebellar nuclei. GCAP-8 expression in the reeler hippocampus and cerebral cortex shows a mixing of layers, which is known to be an aspect of the histological phenotype of this mutant.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Genetics of Pelizaeus-Merzbacher disease.

Pelizaeus-Merzbacher disease (PMD) has been recognized as a clinical entity for more than a century. It has gradually become apparent that the disorder is a dysmyelination, in distinction to demyelinating conditions such as adrenoleukodystrophy. The failure to deposit myelin is due to decreased production of its chief protein, proteolipid protein (PLP). In about 30% of patients with the diagnosis of PMD there is a mutation in the coding portion of the proteolipid protein gene, PLP. This gene is located at Xq22 so the disease in these families shows an X-linked pattern of inheritance. The expression of the mutant gene is generally recessive, but some mutations are expressed frequently in females. At least some patients with PMD that do not show mutations in the coding region of PLP demonstrate linkage between the disease and PLP. As additional mutations in PLP are discovered, it is becoming apparent that the nosology of PLP-associated disease is changing. PMD now comprises a spectrum of disorders with similar but not necessarily identical clinical pictures. Some of these disorders may be certain forms of X-linked paraplegia, SPG2. Finally, some diseases that look like PMD may not be X-linked.

Amino Acid Sequence↗
PubMed1993

Limb-girdle muscular dystrophy is closely linked to the fibrillin locus on chromosome 15.

Limb-girdle Muscular Dystrophy (LGMD) is a rare form of muscular dystrophy inherited as an autosomal recessive trait. The LGMD locus was recently mapped to chromosome 15. We tested the hypothesis that fibrillin is a candidate in the etiology of the disorder by genetic linkage analysis. A large Amish kindred segregating the disorder was genotyped for two markers specific for the fibrillin gene on chromosome 15. A total of 105 individuals were genotyped and a maximum LOD score of Z = 9. 135 at theta = 0.04 was obtained. Our results confirmed the mapping of the LGMD on chromosome 15 and excluded fibrillin as a candidate molecule. These data will be useful in the construction of a fine map of the region surrounding the LGMD locus, a prerequisite for the cloning of the LGMD gene.

Base Sequence↗
PubMed1993

Linkage of a new mutation in the proteolipid protein (PLP) gene to Pelizaeus-Merzbacher disease (PMD) in a large Finnish kindred.

The purpose of this study was to confirm linkage of the proteolipid protein gene (PLP) and Pelizaeus-Merzbacher disease (PMD). A T-->A transversion in nucleotide pair 35 of exon 4 of PLP was found in a large Finnish kindred with PMD. This mutation results in the substitution Val165-->Glu165. We used a combination of single-strand conformational polymorphism and PCR primer extension to determine the presence or absence of the point mutation in family members. A lod score of 2.6 (theta = 0) was found for linkage of the gene and the disease. We examined 101 unrelated X chromosomes and found none with the transversion. This is the second report of linkage of PMD to a missense mutation in PLP. These findings support the hypothesis that PMD in this family is a result of the missense mutation present in exon 4 of PLP.

Base Sequence↗
PubMed1992

Familial occurrence of renal and Müllerian duct hypoplasia, craniofacial anomalies, severe growth and developmental delay.

Absence of the kidneys and of the Müllerian structures has been reported in many patients. We report on a brother and sister, born to nonconsanguineous parents, with renal hypoplasia, Müllerian duct hypoplasia, and strikingly similar facial abnormalities. Both sibs have severe growth and developmental retardation. We think that the unique clinical findings in these sibs represent a new syndrome. The embryological and genetic implications of this condition are discussed.

Abnormalities, Multiple↗
PubMed1992

New variant in exon 3 of the proteolipid protein (PLP) gene in a family with Pelizaeus-Merzbacher disease.

A C--greater than G transversion has been found in exon 3 of the PLP gene of affected males and their mother in a single sibship with Pelizaeus-merzbacher disease (PMD). The transversion should not result in an amino acid change in the protein but it does result in the loss of a HaeIII restriction endonuclease cleavage site. It is concordant with the disease in this family. One-hundred-ten unrelated X chromosomes are negative for this mutation. No other sequence defect was found in the PLP exons of the affected males. The cause of disease in this family remains unknown, but the association between this rare mutation and PMD is intriguing. The mutation can serve as a marker for following segregation of the PLP gene.

Base Sequence↗
PubMed1992

A non-organic and non-enzymatic extraction method gives higher yields of genomic DNA from whole-blood samples than do nine other methods tested.

We compared ten methods for extraction of DNA from whole blood. Nine methods require incubation with either enzymes or treatment of organic solvents or both. The 'Rapid Method' (RM) (Method 10) avoids the use of organic solvents (phenol/chloroform) and eliminates completely the use of proteinase K. Thus, the time and cost of DNA extraction are reduced significantly. This is accomplished by salting out and precipitation of the cellular proteins in saturated sodium chloride. This method takes less than an hour to completion, without compromising the yield or the quality of DNA. Using RM, we can make DNA from 0.1 ml of whole blood and as little as 0.5 ml of blood yields DNA sufficient to run a few Southern blots. The RM can also be applied to packed cells. The DNA is free of RNA, protein and degrading enzymes. The uncut DNA runs as a typical slow-migrating, high-molecular-weight and undegraded species in an agarose gel. The DNA is suitable for digestion by various restriction endonucleases. This procedure works equally well with fresh blood samples and with those that are stored at 4 degrees C and -70 degrees C. To our knowledge the RM reported here is the safest, fastest and most quantitative and economical method for preparation of DNA from whole blood and cells.

Chemistry Techniques, Analytical↗
PubMed1992

Linkage of the Indiana kindred of Gerstmann-Sträussler-Scheinker disease to the prion protein gene.

The Indiana kindred variant of Gerstmann-Sträussler-Scheinker disease has amyloid plaques that contain prion protein (PrP), but is atypical because neurofibrillary tangles like those of Alzheimer disease are present. To map the position of the disease causing gene, we used three markers for linkage analyses. A missense mutation at codon 198 of the PrP gene (PRNP) is found in all definitely affected individuals and yields a maximum lod score of 6.37 (theta = 0). The disease also is concordant with the two other PRNP-region markers. These results demonstrate tight linkage of the disease-causing gene to PRNP and support the hypothesis that the codon 198 mutation is the cause of IK-GSS. Our studies also suggest that methionine/valine heterozygotes at PRNP codon 129 have a later age of onset of the disease than codon 129 valine/valine homozygotes.

Adult↗
PubMed1992

Mutant prion proteins in Gerstmann-Sträussler-Scheinker disease with neurofibrillary tangles.

Two families with Gerstmann-Sträussler-Scheinker disease (GSS) are atypical in possessing neocortical neurofibrillary tangles (NFTs), which are few or absent in other kindreds with GSS, in addition to amyloid plaques that react with prion protein (PrP) antibodies and protease-resistant PrP accumulation in the brain. A leucine substitution at PrP codon 102 has been genetically linked to GSS in some families. We examined the PrP gene in these families. A serine for phenylalanine substitution was found at codon 198 in the Indiana patients; arginine for glutamine substitution at codon 217 in the Swedish patients. These mutations in PrP are the first to be associated with the appearance of both PrP amyloid plaques and neocortical NFTs in GSS patients.

Adult↗