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Biomedical subjects

F H Herrmann

Publications and source records attributed to F H Herrmann.

At least 55 records · Page 3Linked to original sources

Carrier detection of Hunter syndrome (MPS II) by biochemical and DNA techniques in families at risk.

DNA based and biochemical diagnosis of MPS II was performed on 13 unrelated families using Southern blotting. The 35S-sulphate accumulation in cultured fibroblasts was investigated and the iduronate-2-sulphatase (IDS) activity in the serum determined. Sixteen patients and 36 females at risk were screened for structural aberrations and by RFLP analysis using the intragenic probe pc2S15 and probes VK23B, VK21A, and II-10 for the flanking loci DXS297, DXS296, and DXS466. Structural alterations were found in the DNA of two patients. One of them showed a major deletion including the whole coding sequence of the IDS gene. An aberrant Southern fragment occurred in the HindIII/pc2S15 blot of the other patient suggesting a new HindIII restriction site by point mutation in an IDS gene intron. Twenty-nine females were confirmed as carriers, and for five women the heterozygous state could be excluded. Prenatal diagnosis can be offered to 27 women if requested.

Blotting, Southern↗

Structural gene aberrations in mucopolysaccharidosis II (Hunter).

A total of 14 unrelated German patients with X-linked iduronate-2-sulfatase (IDS) deficiency (Hunter syndrome, MPS II) showing variable clinical manifestations was screened for structural gene aberrations by Southern analysis. Using the IDS cDNA clone c2S15 as a probe, no Southern fragments could be detected in blots in the severely affected patient G-65 with respect to DNA digested by HindIII, PstI and TaqI, suggesting a total loss of the IDS structural gene. In this patient, the flanking loci DXS 297, DXS 296 and DXS 466 were tested. The locus DXS 466 is involved in the deletion, whereas both of the other loci are present. A normal 9.0-kb fragment disappeared and an aberrant fragment of 3.5 kb occurred in the HindIII blot of patient G-117. A normal Southern pattern was found in PstI and TaqI blots of this patient. This result can be interpreted as the generation of an additional HindIII restriction site by point mutation in an IDS gene intron.

Blotting, Southern↗

Segregation and sporadic cases in families with Hunter's syndrome.

Segregation analysis on five samples of families with Hunter's syndrome (158 cases overall) shows that the mutant allele segregates in agreement with Mendelian expectations for an X linked recessive disease, but the proportion of sporadic cases is significantly lower than expected under mutation-selection equilibrium. Heterogeneity among the samples is apparent, but it is caused entirely by a sample of Ashkenazi families, whose segregation pattern has previously been interpreted as supporting the hypothesis of prenatal selection in favour of the pathological allele. Conversely, our joint analysis of the five samples by a maximum likelihood approach does not suggest segregation distortion. Possible reasons for the apparent lack of sporadic cases include the effect of ascertainment bias.

Alleles↗

Evidence supporting tight linkage of X-linked Emery-Dreifuss muscular dystrophy to the factor VIII:C gene.

In a large German family with Emery-Dreifuss muscular dystrophy (EDMD) linkage analysis was performed using the factor IX gene (F9), the factor VIII:C gene (F8), the anonymous DNA probe DXS52, and DXS15 as markers. Tight linkage was found between the EDMD locus and the F8 probe (Zmax = 1.19; theta max = 0.00), DXS15 (Zmax = 1.75; theta max = 0.00) and DXS52 (Zmax = 2.26; theta max = 0.00). Weak linkage was found to F9 (Zmax = 0.02; theta max = 0.43). The data from the literature and our results suggest that the gene locus of EDMD is close to F8 (confidence interval theta = 0-0.07). The new linkage data are useful for carrier detection and diagnosis of EDMD patients before onset of major clinical signs.

Cardiomyopathies↗

The immunological evidence for a phenylalanine hydroxylase like immunoreactive protein in different human cells and tissues.

Phenylalanine hydroxylase (PAH) was purified 105-fold from human liver. The rel mol mass of the subunits in sodium dodecylsulfate-polyacrylamide gel electrophoresis was 54,000 Da and the isoelectric point was estimated to be between pH 5.0 and 5.2. The activity of purified PAH was inhibited by p-Cl-phenylalanine (p-Cl-Phe), 3-J-tyrosine (3-J-Tyr) and 6-F-tryptophane (6-F-Trp) by 73%, 26% and 10%, respectively. The Km value was 0.36 x 10(-3) mol/l for L-Phe and 5.88 x 10(-5) mol/l for the synthetic cofactor dimethyltetrahydrobiopterin (DMPH4). Polyclonal antibodies raised in rabbits against the active human enzyme showed only a slight cross-reaction with purified rat liver PAH. Using the rabbit antibodies an immunoreactive protein with the same mol mass and isoelectric point as purified human liver PAH and PAH from crude liver extract was detected in extracts from kidney, heart, spleen, brain, pancreas, lung, placenta, leucocytes, cultured skin fibroblasts and chorionic villus cells.

Enzyme-Linked Immunosorbent Assay↗

Prenatal diagnosis of haemophilia A by the polymerase chain reaction using the intragenic hind III polymorphism.

A method is described which uses the Hind III polymorphism in intron 19 of the factor VIII gene for genomic family analysis and prenatal diagnosis by the polymerase chain reaction. The primers derived from the exon 19 and 20 sequences allow amplification of the whole intron 19 resulting in a 730 bp fragment. Hind III restriction of this fragment provides fragments of 250 bp or 160 bp and 90 bp respectively, specific for the intragenic Hind III polymorphism. The constant 480 bp fragment can be used as an internal control to circumvent misdiagnosis due to incomplete or failure of restriction. Using this method a prenatal diagnosis of haemophilia A in the first trimester of pregnancy is demonstrated.

Base Sequence↗

A new marker at DXS 115 useful for carrier detection in hemophilia A.

In this brief communication we report a new intergenic polymorphism at DXS115 as a marker for detection of heterozygotes in families at risk for hemophilia A. Total genomic DNA was isolated from white blood cells, double digested by KpnI and XbaI and hybridized with EcoRI/SstI fragment of the genomic probe p482.6. The incidence of the polymorphic 5.1-kb fragment was estimated as 0.069 in a German population. A technical advantage of using the XbaI/KpnI RFLP is that both the intragenic XbaI-RFLP in intron 22 of factor VIII gene and the new intergenic RFLP can be evaluated at the same time.

Female↗

Characterization of three new deletions at the 5' end of the HPRT structural gene.

In a panel of seven unrelated HPRT-deficient patients three partial deletions of the 5' end of the HPRT structural gene were identified by Southern blot analysis. The deletions could be defined as the loss of exons 1-3, exons 2-3 and exon 3 respectively. In two of the deletion mutations aberrant restriction fragments occurred.

Blotting, Southern↗

Deletion screening and prenatal diagnosis of Duchenne muscular dystrophy using cDNA probes Cf 23a and Cf 56a.

We have screened patients of 14 families at risk for Duchenne muscular dystrophy (DMD) from the northern part of the German Democratic Republic using the cDNA clones Cf 23a and CF 56a. Of the 14 unrelated DMD families, 7 (50%) showed different deletions with these cDNA probes. A prenatal diagnosis by chorionic villi sampling was performed in a DMD family with patients showing a deletion of the 5.4 kb Pst I band detected by the cDNA probe Cf 56a. This band corresponds to a 10 kb exon region of the cDNA probe 8 of Koenig et al. The patient's mother was informative only for the flanking marker 99.6. The male fetus showed the same haplotype and the same deletion as the two patients.

Chromosome Deletion↗

RFLP analysis for diagnosis of haemophilia A in the German Democratic Republic.

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.

DNA↗

Deletion analysis of DMD/BMD families from the German Democratic Republic and selected regions of Czechoslovakia and Hungary.

Over the last two years we have screened 183 DMD/BMD families requesting prenatal diagnosis. Using cDNA probes cf56a,b we have detected exon deletions in 72 of them. In 62 cases the deletion was also detectable with currently available PCR primers. Deletion analysis for exons 8, 17, and 19, using either PCR or Southern blotting techniques, was performed for 65 of the 111 families which showed no deletions with cf56a,b. Eight of them were deleted for one or more of these exons. PCR offers new possibilities for deletion analysis in families without a living patient using either Guthrie papers or histologically conserved material from the dead patient. In 20 of 25 patients, we observed concordance between the clinical picture and the molecular deletion analysis in accordance with the open reading frame hypothesis. Five patients, however, presented with DMD in spite of our analysis showing an in frame deletion. Carrier determination in families in which DMD is caused by a deletion using linkage, dosage, or breakpoint analysis is discussed.

Blotting, Southern↗

Proliferation and differentiation of cultured epidermal cells from patients with X-linked ichthyosis and ichthyosis vulgaris.

The growth, differentiation, and regeneration of epidermal cultures from patients with X-linked and autosomal dominant ichthyosis and normal individuals were compared. Cell proliferation was studied by combining the technique of fluorescence-activated cell sorting with [3H]thymidine labelling and autoradiography. As in normal epidermal cultures, a marked heterogeneity in the labelling intensity of S-phase cells was observed in the ichthyotic cultures with totally unlabelled as well as very strongly labelled cells. However, in contrast to normal cultures, by far the largest proportion of S-phase cells in the ichthyotic cultures were very strongly labelled with a corresponding, severe reduction in the proportion of un- and weakly labelled cells. The increased labelling intensity of S-phase cells was observed in primary as well as in regenerating cultures, although it was most pronounced in the latter case. There was no difference between cultures from the two types of ichthyotic skin. The morphologic differentiation in the cultures was assessed by measurement of mean diameter of sorted S-phase cells and by quantitation of cornified envelop formation. Both parameters were reduced in the ichthyotic cultures, compared with normal ones. Taken together, these findings are indicative of a hyperproliferative state in the ichthyotic cultures.

Biopsy↗

Genomic diagnosis of haemophilia A and B in the German Democratic Republic.

Since 1986 the genomic diagnosis of haemophilia A and B in the GDR is realized as a national programme. Until Aug. 1989 56 families at risk of haemophilia A are analysed using RFLPs of different intragenic and intergenic probes (BclI/F8e 16-19, KpnI-XbaI/int 22, TaqI/St 14.1). 117 out of 162 females at risk being heterozygous were identified as carriers, in 40 cases the carrier state was excluded, and in 5 females the data were not informative. Prenatal diagnosis was offered to 93 carriers in reproductive age. Six genomic prenatal diagnoses in haemophilia A were performed. In four patients different partial deletions of factor VIII:C gene were found. 10 families of haemophilia B were analysed using intragenic and intergenic probes (P 1; pX58dIIIc). 14 females were identified as carriers, 11 were excluded. The application of direct and indirect gene diagnosis in haemophilia is discussed.

Chromosome Deletion↗

Genomic carrier detection and prenatal diagnosis of haemophilia A in families at risk using the polymerase chain reaction (PCR).

The polymerase chain reaction (PCR) was applied in genomic analysis of families at risk for haemophilia A using the intragenic Bel I and Hind III polymorphism in introns 18 and 19, respectively, of factor VIII gene. For the latter the primers derived from exon 19 and 20 sequences allowed to amplify the whole intron 19 resulting in a 730 bp fragment. Hind III restriction of this fragment provides polymorphic fragments of 250 bp or 160 bp and 90 bp respectively. An also occurring 480 bp fragment can be used as internal control to circumvent misdiagnosis due to incomplete or failure of restriction. The Hind III polymorphism was successfully used in prenatal diagnosis of an affected male in the first trimenon of pregnancy. Fetal sexing was also performed by PCR technique using Y specific primers.

Base Sequence↗

Prenatal diagnosis of phenylketonuria by haplotype analysis.

Prenatal diagnosis of classic phenylketonuria (PKU) was performed after chorionic villus sampling by means of linked restriction fragment length polymorphisms (RFLPs) using the cDNA probe ph PAH 247 (Kwok et al. (1985) Biochemistry, 24, 556-561). We report in this paper a PKU family who were only informative for RFLP analysis by a combination of two RFLPs on the basis of haplotype determination of the normal and mutant phenylalanine hydroxylase (PAH) alleles. The DNA analysis detected a PKU fetus homozygous for mutant PAH alleles and the mother opted for termination in the 12th week of gestation.

Chorionic Villi Sampling↗

Deletion screening in patients with Duchenne muscular dystrophy.

DNA of 35 patients with Duchenne muscular dystrophy (DMD) from 27 unrelated families from the northern part of GDR, Czechoslovakia and Hungary were analysed by means of 9 genomic probes and cDNA probes Cf 23a and Cf 56a, which detect exons of the central part of the DMD gene. Of the unrelated DMD patients, 63% have deletions for one or more intragenic and/or cDNA probes and 33% have deletions for genomic probes, mostly for pERT 87 (15%) and P 20 (15%). 48% of the DMD patients have deletions for one or more exon regions detected by Cf 56a and Cf 23a. The deletions were mapped. The genomic probe P 20 and the distal part of the cDNA probe Cf 23a detected the same part in the centre of the DMD gene. The deletions are heterogeneous in size and extent. In patients of the same family, identical deletions were detected in the DMD gene. The detection of deletions is useful for prenatal diagnosis and carrier detection.

Chromosome Deletion↗

Gene diagnosis in X-linked ichthyosis.

Three families segregating for X-linked ichthyosis (XLI) were analysed using the full-length STS cDNA probe and an anonymous polymorphic DNA sequence closely linked to the STS gene. In patients from two of the families, submicroscopic chromosomal deletions could be detected using both the STS and the GMGX9 (DXS237 locus) probes. Patients in the third family showed the same hybridization pattern as healthy males following molecular hybridization with either of the probes. The results of DNA analysis (indirect genotype diagnosis) agree well with those based on the arysulfatase C/beta-gal determination and prove the reliability of the biochemical test. Both methods are discussed for carrier detection, prenatal diagnosis, and genetic counseling.

Arylsulfatases↗