摘要:

AbstractPEG‐ADA is a long‐circulating form of adenosine deaminase (ADA) that has been in use for<8 years as replacement therapy for severe combined immunodeficiency disease due to ADA deficiency. Treatment with PEG‐ADA almost completely corrects metabolic abnormalities, allowing the recovery of a variable degree of immune function. Although not normal, the level of function achieved has in most cases been sufficient to protect against opportunistic and life‐threatening infections. PEG‐ADA has been used as an alternative for patients who lack an HLA‐identical bone marrow donor, but are judged to be at too high a risk for undergoing HLA‐haploidentical marrow transplantation. To date, mortality and morbidity with PEG‐ADA have been less than for the latter procedure. PEG‐ADA has also been an important adjunct to attempts to develop somatic cell gene therapy for ADA deficiency, although its continued use poses a problem for evaluation of the benefit of gene therapy. As a true “orphan drug” developed to treat a very small patient population, the cost per patient of PEG‐ADA is very

ISSN:1059-7794    

DOI:10.1002/humu.1380050202

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

年代:1995

数据来源: WILEY

摘要:

Abstractβ‐Ketothiolase deficiency is a deficiency in mitochondrial acetoacetyl‐CoA thiolase (T2). We present here an update on mutations and polymorphisms in the human T2 gene. No large deletion or insertion has been observed in Southern blot analysis. Seventeen mutations were identified in 13 T2‐deficient patients: nine missense, one nonsense, and five splice‐site mutations, and two small deletions. Two polymorphic base substitutions were also detected. A common mutation in T2 deficiency has not been detected but 4 mutations (N158D, Q272X, 828+1, 1163+2) were identified in two independent families. Eleven of 25 mutant alleles identified caused aberrant splicing. In vivo expression analysis of 13 mutant cDNAs using a Lipofectin reagent suggested that T297M, A301P, and A380T mutant alleles retain 5‐10% normal T2 activity. A correlation between clinical phenotype and genotype in T2 deficiency seems unlikely. © Wile

ISSN:1059-7794    

DOI:10.1002/humu.1380050203

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

年代:1995

数据来源: WILEY

摘要:

AbstractSchmid metaphyseal chondrodysplasia (SMCD) has previously been shown to be the result of mutations in the type X collagen gene, COL10A1. A further three mutations have been identified, including two nonsense mutations (Y268X, W651X) and a frameshift mutation (1856delCC). Each of the 10 SMCD mutations identified to date is within the C‐terminal noncollagenous domain of type X collagen and three of five deletions initiated around the same nucleotide. This domain is believed to be involved in the initiation of collagen trimerization. The concentration of mutations within this domain is consistent with the hypothesis that the phenotype is the result of a reduction in the level of mature type X collagen due to the mutant polypcptide's inability to participate in trimer formation, although a dominant‐negative mechanism cannot be discounted, on the basis of current evidence. © Wiley‐Lis

ISSN:1059-7794    

DOI:10.1002/humu.1380050204

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe frequency of 12 different mutations of the steroid 21‐hydroxylase gene (CYP21) was investigated in 129 French patients affected by congenital adrenal hyperplasia (CAH) due to steroid 21‐hydroxylase deficiency. Eighty‐nine percent of the CAH chromosomes were characterized. The most frequent mutations were a C‐G substitution in intron 2, the deletion of the CYP21 gene and a T‐A substitution in exon 4 in the severe form of the disease, and a G‐T substitution in exon 7 in the nonclassic form. The correlation between the genotypes and the clinical forms of the disease showed marked variation in the phenotype from a single genotype, suggesting that individual variation and undetected additional mutations on the same CAH chromosome accounted for the phenotype. In 65 informative meioses of CAH families, no de novo mutation was found. © Wil

ISSN:1059-7794    

DOI:10.1002/humu.1380050205

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

年代:1995

数据来源: WILEY

摘要:

AbstractMutations in 21 hydroxylase gene were investigated in 40 Russian patients with congenital adrenal hyperplasia. Quantitative amplification/restriction procedure was used for detection of mutations involving promoter region, 3 and 8 exons. For affected chromosomes alleles of tightly linked HLA A and B genes were defined, as well as 5 different alleles or allele combinations of HLA DQA1 gene. The most frequent (>20% of chromosomes) cause of salt wasting adrenal hyperplasia in Russia is a chimeric CYP21A‐CYP21B gene with normal copy of a pseudogene which results from gene conversion in chromosome with B14‐DQA1 0101/0102 haplotype. The second common mutation (about 10%) is a result of intragenic recombination well‐known deletion of the gene linked with A3‐B47‐DQA1 0201/0601 haplotype. Two other mutations were linked with A3‐B35‐DQA1 0401/0402 and A3‐B40‐DQA1 0201/0601 haplotypes.

ISSN:1059-7794    

DOI:10.1002/humu.1380050206

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

年代:1995

数据来源: WILEY

摘要:

AbstractLate infantile metachromatic leukodystrophy (MLD) is a neurodegenerative disease, most commonly caused by the deficiency of the lysosomal enzyme arylsulfatase A (ARSA). Late infantile MLD is frequent (1/75 live birth) in a small Jewish community which lived in Habban, isolated from the other Jewish populations. The gene coding for ARSA was sequenced in one of the Habbanite patients, who was found to be homozygous for an allele having three mutations. Two mutations are A to G transitions in the ARSA gene at positions 1788 and 2723, causing the loss of an N‐glycosylation site and a polyadenylation signal, respectively. These mutations are characteristic for the ARSA pseudodeficiency (PD) allele, which in homozygozity is associated with low enzymatic activity, but does not cause‐disease. The third mutation, which occurred on the background of the PD allele, is a C to T transition at position 2119, predicting a substitution of proline‐377 by leucine (P377L). Biosynthesis studies performed with cells expressing the ARSA cDNA into which this mutation was introduced demonstrated a severely reduced half‐life of the mutant enzyme. Five of 10 patients from the Habbanite community could be studied and were homozygous for the P377L allele. These observations confirm the genealogical data which pointed to a common ancestor for all the carriers of MLD among the Habbanite Jews. In addition, the same mutation was demonstrated to be relatively frequent among the Yemenite Jews. The origin and the means by which the mutation spread between the two communities remain unknown. © Wiley

ISSN:1059-7794    

DOI:10.1002/humu.1380050207

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

年代:1995

数据来源: WILEY

摘要:

AbstractGermline mutations of the adenomatous polyposis coli (APC) gene tend to cluster in discrete regions, Some of these mutations occur frequently in familial adenomatous polyposis coli (FAP) patients, and strategies for genetic diagnosis of the disease should include simple methods for their detection. We studied a total of 48 FAP‐affected or “at‐risk” members from 31 unrelated FAP pedigrees. Unrelated patients were analyzed using heteroduplex analysis on agarose minigels (HAAM) and multiplex allele‐specific PCR. This novel strategy readily and reliably detected the three frequently occurring APC deletions at codons 1061, 1068, and 1309, allowing identification of mutant alleles in nine unrelated patients. A targeted mutational analysis, based on HAAM and amplification refractory mutation system (ARMS), allowed the rapid identification of 11 additional subjects with germline deletions, among relatives of the patients in whom mutations had been detected by multiplex PCR and HAAM. The use of two independent PCR‐based tests, employing distinct sets of primers, reduces the possibility that artifacts occurring during DNA amplification may interfere with the diagnostic evaluation. The analysis of genotype‐phenotype correlations provided evidence for heterogeneity with regard to the extent of colonic and extracolonic manifestations of the disease in subjects bearing identical mutations. However, the consistent association of the deletion at codon 1309 with more severe colonic disease than that observed in patients with mutations at codons 1061 and 1068, supports a correlation between mutation site and penetrance of FAP. © W

ISSN:1059-7794    

DOI:10.1002/humu.1380050208

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

年代:1995

数据来源: WILEY

摘要:

AbstractIsolation of the gene for cystic fibrosis (CF), the cystic fibrosis transmembrane conductance regulator (CFTR), provided a basis for analyzing its molecular pathology and resulted in the identification of5% of CF chromosomes in most populations, and most mutation frequencies are96% of CF mutant chromosomes worldwide. Mutations were detected by competitive oligonucleotide probe ligation to detect normal and/or mutant genotypes in one reaction. Three probes (one common and two allelic probes) were needed for analysis of each mutation. Probes hybridized to target DNA were joined by a thermostable ligase if there were no mismatches at their junctions; temperature cycling resulted in a linear increase in product. Common probes were labeled with fluorochromes, and allelic probes each had different lengths. Ligation products were analyzed electrophoretically on a fluorescent DNA sequencer. The results show that combined PCR and probe ligation amplification rapidly and reliably screen for CF homozygotes and carriers. © Wiley‐Liss

ISSN:1059-7794    

DOI:10.1002/humu.1380050209

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

年代:1995

数据来源: WILEY

摘要:

AbstractThe use of universal heteroduplex generators (UHG) as an effective means of screening for specific mutations has been previously reported. Here, we report the optimisation of a UHG system used for the rapid and simple detection of sickle cell hemoglobinopathies, HbS and HbC. The test involves heteroduplex formation between between polymerase chain reaction (PCR)‐amplified β‐globin gene first exon sequences, and a UHG. The UHG is a synthetic DNA molecule homologous to HbA but which contains a small deletion adjacent to the HbS and HbC mutation sites in codons 5 and 6. Heteroduplexes are resolved on nondenaturing polyacrylamide minigels and are diagnostic of HbS and HbC in homozygous and heterozygous individuals. A blind trial of UHG genotyping involving eleven previously sequenced DNAs showed complete concordance between methods. In addition, we identified a characteristic heteroduplex banding pattern for the H2H silent mutation (CAC → CAT) in codon 2. © Wiley‐

ISSN:1059-7794    

DOI:10.1002/humu.1380050210

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

年代:1995

数据来源: WILEY

ISSN:1059-7794    

DOI:10.1002/humu.1380050211

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

年代:1995

数据来源: WILEY