摘要:

AbstractIn 1988, by using the powerful and accurate cDNA/PCR technique, it was demonstrated that there are very low levels of dystrophin mRNA in a variety of non‐muscle tissues, including cultured fibroblasts and lymphoblastoid cell lines. The phenomenon was also shown for a number of other tissue‐specific genes, including β‐globin, factors VIIIc and IX, anti‐Müllerian hormone, L‐pyruvate kinase, retinal blue pigment, phenylalanine hydroxylase. The level of transcript in inappropriate cells is exceedingly low, perhaps one mRNA per 100–1000 cells. This low‐level ubiquitous transcription of tissue‐specific genes was called “illegitimate” or “ectopic” transcription, and has been proven to occur for 17 gene transcripts to date. The mechanism and biological significance of illegitimate transcription are still obscure, but, since illegitimate transcripts exhibit the same pathology as legitimate transcripts, they have been useful tool in the study of already 9 inherited diseases. This strategy will be applied widely for diseases where samples from the appropriate tissue for study is difficult to obtain, or where an mRNA is easier or more informative to study than a genomic DNA (as for large genes, or where alternative splicing is involved

ISSN:1059-7794    

DOI:10.1002/humu.1380010502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis article provides a review of the mutations reported so far in the lysosomal storage disease aspartylglucosaminuria (AGU). The clinical symptoms, biochemical findings, and diagnostic possibilities of the disease are introduced. The prevalence and biological consequences of the found mutations are then described, as well as the availability of a new rapid DNA test suitable for carrier screening. This test will be especially applicable in the genetically isolated Finnish population, where the carrier frequency of AGU was found to be as high as 1:36. Finally, future prospects dealing with the foreseeable therapeutic interventions of the disease are discussed. © 1992 Wiley‐Liss, I

ISSN:1059-7794    

DOI:10.1002/humu.1380010503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe Marfan syndrome is an autosomal dominant heritable disorder of connective tissue with prominent involvement of the ocular, skeletal, and cardiovascular systems. The gene on chromosome 15 encoding fibrillin (FBN1), a 350‐kDa glycoprotein component of the extracellular microfibril, is the site of defect in most, if not all cases. Complementary DNA sequence reveals a gene composed largely of epidermal growth factor‐like repeats, each containing six predictably spaced cysteine residues. To date, two FBN1 gene missense mutations have been reported. Here we describe the identification of three new missense mutations in the FBN1 gene in patients with the Marfan syndrome. All of the 5 characterized missense mutations occur within the epidermal growth factor‐like repeats of the FBN1 gene. In addition, 4 of 5 involve the substitution of cysteine residues and 3 of 5 substitute the third cysteine in the epidermal growth factor‐like motif consensus sequence. These data suggest that defined residues within EGF‐like domains of FBN1 have particular significance and, when altered, play a pivotal role in expression of the Marfan phenotype. © 1992 Wiley

ISSN:1059-7794    

DOI:10.1002/humu.1380010504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe majority of the identified cystic fibrosis (CF) mutations are very uncommon in the total patient population, making the correlation between the clinical presentation and the molecular alterations difficult. The largest deletion that has been described so far in CF is of 84 bp in exon 13, which corresponds to the regulatory (R) domain of the CF transmembrane conductance regulator (CFTR) protein. We have analysed 340 Spanish CF patients for this deletion, named 1949del84, and found three further compound heterozygous patients for mutations 1949del84 and ΔF508, and one for 1949del84 and an unknown mutation. Evaluation of the clinical data in these patients suggests that this in‐frame deletion, when associated with ΔF508, has a similar disease severity to that of ΔF508 homozygous patients. © 1992 Wiley‐Li

ISSN:1059-7794    

DOI:10.1002/humu.1380010505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractCystic fibrosis, the most common lethal genetic disease in the white population, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Analysis of DNA from a pancreatic insufficient patient by chemical mismatch cleavage and subsequent DNA sequencing led to the identification of a potential splice mutation in the CFTR gene. A transition of the invariant guanosine to adenosine (1898+1G>A) was found at the splice donor site of intron 12. To determine the effect of this mutation on the patient's CFTR transcripts, RNA from the nasal epithelium was reverse transcribed and amplified by the polymerase chain reaction (RT‐PCR). Direct sequencing of the PCR products revealed that the transcript from the chromosome with the 1898+1G>A mutation had skipped exon 12 entirely, resulting in a joining of exons 11 and 13. Deletion of exon 12 results in the removal of a highly conserved region which encodes the Walker B consensus sequence of the first nucleotide‐binding fold of CFTR. © 1992 Wiley‐Lis

ISSN:1059-7794    

DOI:10.1002/humu.1380010506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractWe here describe the detection of a de novo mutation in the phenylalanine hydroxylase gene in a Norwegian phenylketonuria (PKU) patient. This novel mutation, M1I, disrupts the start codon of the gene by a G to A transition. The compound heterozygote genotype (IVS‐12/M1I) of this patient predicts that no phenylalanine hydroxylase enzyme is formed, thus leading to a severe classical PKU. Determination of haplotypes and DNA fingerprint patterns indicates a paternal origin of the de novo mutation. © 1992 Wiley‐Liss,

ISSN:1059-7794    

DOI:10.1002/humu.1380010507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractAcute intermittent porphyria (AIP) is a dominantly inherited metabolic disease caused by a partial deficiency of the third enzyme, porphobilinogen deaminase (PBGD), in the heme biosynthetic pathway. AIP has been divided into two subtypes according to the ratio of enzyme polypeptide concentration and enzyme activity measured in erythrocytes: cross‐reacting immunologic material (CRIM) positive or negative. In this study six out of the seven known CRIM‐positive AIP families in Finland were analyzed and two also previously identified mutations in the PBGD gene were found to be responsible for AIP in this genetically isolated population. The search for mutations was focused on exon 10 based on previously found mutations. SSCP analysis revealed a known polymorphism but the two mutations in that region were found only by direct sequencing of the PCR products. A G518→ A substitution changing Arg173to Gln was found in three families and a C499→ T substitution changing Arg167to Trp was detected in three families. DNA analyses of the family members revealed that conventional assays of erythrocyte PBGD activity identified correctly only 72% of the carriers for the AIP mutation. © 1992 Wiley

ISSN:1059-7794    

DOI:10.1002/humu.1380010508

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractMaroteaux‐Lamy syndrome (mucopolysaccharidosis type VI, MPS VI) is an autosomally inherited lysosomal storage disorder caused by a deficiency ofN‐acetylgalactosamine‐4‐sulfatase (EC 3.1.6.1; 4‐sulfatase). In order to determine the gene defect in a clinically severe MPS VI patient, polymerase chain reaction (PCR) products were generated from the patient's fibroblast mRNA and also from a 4‐sulfatase cDNA clone and subjected to the chemical cleavage technique to detect mismatched bases, which were then identified by direct DNA sequencing of the PCR products. The patient was homozygous for an early frameshift mutation caused by the deletion of a G at position 238 (ΔG238), which produces a truncated 4‐sulfatase with an altered amino acid sequence from amino acid 80 to a premature stop codon at codon 113 relative to the normal 4‐sulfatase reading frame of 533 amino acids. Since the mutation occurs only 40 amino acids past the signal peptidase cleavage site, it is most likely that this will result in a protein with no 4‐sulfatase activity. This is consistent with the severe clinical presentation and the absence of 4‐sulfatase enzyme activity or mutant 4‐sulfatase protein in the patient. The patient was also found to be homozygous for two polymorphisms, i.e., a G to A transition at nucleotide 1072 resulting in a valine358to methionine substitution (V358M) and a silent A to G transition in the third base of the proline397codon at nucleotide 1191.

ISSN:1059-7794    

DOI:10.1002/humu.1380010509

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe direct sequencing of the human type II procollagen (COL2A1) gene from polymerase chain reaction (PCR)‐amplified genomic DNA is described. Thirty‐two regions of the COL2A1 gene were asymmetrically amplified with intron primers which were specifically chosen to amplify a region spanning 500 to 800 bp of sequence encoding one or more exons and their accompanying intervening sequences. Primers for dideoxynucleotide sequencing of the PCR products were then designed to provide complete exon sequence information and to insure that intron:exon splice junction sequence data would be obtained. Amplification and sequencing reactions were performed on an automated workstation to facilitate the handling of multiple DNA templates. The procedure allowed efficient sequencing of over 25,000 bp of each allele of the COL2A1 gene per diploid genome. We used this method for the comparative analyses of COL2A1 sequences in DNA isolated from the blood of 42 unrelated individuals and we identified 21 neutral sequence variants in the gene. The sequence variations were confirmed by independent assays, including restriction enzyme digestion. The sequence variants described here will be important for identifying haplotypes of the type II procollagen gene that will be useful in defining a genetic etiology for diseases of cartilaginous tissues. © 1992 Wiley‐Lis

ISSN:1059-7794    

DOI:10.1002/humu.1380010510

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThe allele‐specific PCR approach has been modified by introducing a second mismatch at the 3′‐penultimate link of the primer and used to identify the sickle cell anemia mutation (A → T transversiion in the sixth codon of the human β‐globin gene causing Glu → Val substitution in the protein), thus obviating the problem of an interpretationally ambiguous 3′‐terminal mismatch including T residue. © 199

ISSN:1059-7794    

DOI:10.1002/humu.1380010511

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY