ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03382.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The approaches to carrier detection and prenatal diagnosis of the fragile X syndrome using DNA probes are described. Since the definitive diagnosis rests upon the cytogenetic demonstration of the fragile X, molecular diagnoses are essentially confined to fragile X family members in whom the fragile X cannot be demonstrated. Since none of the polymorphic probes available are tightly linked to the fragile X, the preferred approach is to use probes which flank the fragile site. Useful probes are listed and suggested recombination fractions for use in diagnosis are given. A strategy is outlined for obtaining the closest informative flanking markers with the minimum amount of laboratory effort. Methods of risk analysis are discussed. It is concluded that molecular analysis is very useful for carrier detection but of limited use in prenatal diagnosis.

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03383.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The frequencies of Bcl I, Hind III and Xba I intragenic polymorphic sites in the population of the GDR were found to be 0.68, 0.38 and 0.48, respectively. No differences in composition and frequencies were detectable at DXS 52 locus in comparison with other Caucasian populations. A strong linkage disequilibrium between the intragenic Bcl I and Hind III sites could be confirmed. The observed heterozygosity for the flanking marker DXS 52 in combination with intragenic Bcl I and Xba I polymorphisms was 0.97.Using these three RFLPs, 122 females at risk in 41 independent haemophilia A families were investigated; 86 of them could be identified and 27 excluded as carriers; 9 females could not be classified. So far, four prenatal diagnoses in the first trimester of gestation have been performed by RFLP analysis.

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03384.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

A mother and two daughters are presented with severe short stature with disproportionately short limbs, small hands, clinodactyly, valvular heart disease and a distinctive facies with ptosis, high‐arched palate and crowded dentition. This appears to be a previously undescribed syndrome, probably inherited as an autosomal dominant trai

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03385.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Eighty‐three infants and children with a professional diagnosis of Down syndrome were studied cytogenetically. The results showed that 81.9% of them were trisomy 21 and 18.1% were the 46/47 + G type of mosaic. All cases were distributed according to parental consanguinity. The results showed that 77.9%, 16.2% and 5.9% of the trisomy 21 cases, and 53.3%, 26.7% and 20.0% of the mosaic cases were from non‐consanguineous, First‐cousin and second‐cousin marriages, respectively. By combining all the cases, these percentages were 73.5%, 18.1% and 8.4%, respectively. Considering the high rate of inbreeding in Iraq (inbreeding coefficient = 0.0225) and using various statistical comparisons, these results revealed the lack of evidence for genetical control of non‐disjuncti

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03386.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

We report our findings in four cases of metachromatic leukodystrophy diagnosed in Greece during the last 4 years. The age of onset and the clinical symptoms were those described for the late infantile form of the disease. However, one patient retained his speech and mental abilities despite his pronounced motor regression and neurological involvement. This was combined with high residual arylsulphatase A activity in white blood cell homogenates even in the 0°C incubation assay

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03387.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The addition of two new markers in maternal serum, estriol and HCG, to those already known, namely the level of maternal serum alfa‐fetoprotein and maternal age, considerably improves the expected results of a screening strategy for Down syndrome. The detection rate is slightly increased from 53.0% to 57.6%, but, more importantly, the false‐positive rate decreases from 9.4% to 7.3%. It is our belief that, at least in women aged less than 35 years, a screening strategy based on a combination of maternal age and biochemical markers should be incorporated into antenatal care. For older women, the results of such a maternal serum test may refine counseling for genetic amniocentesis, as a much more explicit risk calculation can be performed than that based on age al

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03388.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

The autosomal dominant prealbumin amyloidoses are late‐onset disorders characterized by varying degrees of peripheral neuropathy, nephropathy and cardiomyopathy. To date, seven different single amino acid mutations in the plasma protein prealbumin (transthyretin) have been found to be associated with amyloidosis and each is the result of a single nucleotide change in the prealbumin gene. By virtue of the restriction endonuclease sites created by the point mutations which give rise to the protein variants, direct DNA tests using Southern analysis have already been developed for detection of the Met‐30, Ile‐33, Ala‐60, Tyr‐77 and Ser‐84 prealbumin genes. As an alternative to Southern analysis, we have amplified discrete regions of the prealbumin gene using polymerase chain reaction (PCR) and used restriction enzyme analysis of the PCR products to detect the Met‐30, Ala‐60, Tyr‐77 and Ser‐84 prealbumin genes after agarose gel electrophoresis and staining with ethidium bromide. In comparison to Southern analysis these alternative tests yield results much more quickly and avoid the use and handling of radioacti

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03389.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Four hundred and thirty‐nine Chinese schizophrenic male patients were investigated for the distribution of haptoglobin types; transferrin and group‐specific component subtypes. The allelic frequencies of these three polymorphisms in the patient group were compared with those in healthy controls from published series. An excess ofGc2overGc1(X214.1;P<0.05) as well as a lack ofGclS(X2115.3;P<0.001) was observed in schizophrenia. The relative risks ofGc1F,Gc1SandGc2have been estimated as 1.12, 0.76 and 1.15, respectively. It appears from this study that the presence ofGc2renders individuals susceptible whileGc1Soffers protection for schizophrenia. No such association was found for the haptoglobin or transferrin polymorphi

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03390.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

This brief report describes a mother and two daughters with the rare Buschke‐Ollendorff syndrome. That the typical dermal connective tissue naevi lesions may become less obvious with time and that the condition is not always so “benign” are important clinical features not well recognised. Incorrect diagnosis may lead to embarkation upon hazardous manag

ISSN:0009-9163    

DOI:10.1111/j.1399-0004.1990.tb03391.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY