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P Propping

Publications and source records attributed to P Propping.

At least 181 records · Page 10Linked to original sources
PubMed1993

Molecular diagnosis of trisomy 18 using DNA recovered from paraffin embedded tissues and possible implications for genetic counselling.

Severe malformations pointing to trisomy 18 were observed in two fetuses. No chromosome analysis had been performed. To confirm the diagnosis of trisomy 18, DNA was isolated from formalin fixed and paraffin embedded tissues. Molecular analysis by typing chromosome 18-specific (CA)n-repeats unequivocally showed the presence of trisomy 18 in both cases.

Chromosomes, Human, Pair 18↗
PubMed1993

Predictive diagnosis in familial adenomatous polyposis: evaluation of molecular genetic and ophthalmologic methods.

Familial adenomatous polyposis (FAP) is an autosomal-dominant precancerous condition characterized by the appearance of hundreds to thousands of colorectal polyps. The responsible gene (APC) has been mapped and identified. The cancer prevention policy for persons at risk (children and sibs of FAP patients) implies an early diagnosis of the disease. A presymptomatic diagnosis allows to limit the regular rectosigmoidoscopic examination to those persons having inherited the disease gene. Presymptomatic diagnosis can be achieved by molecular genetic methods (direct and indirect genotype analysis) and by funduscopic examination of retinal pigment anomalies that are characteristic for FAP. The aim of this study was to examine the power of the molecular genetic and ophthalmologic methods for presymptomatic diagnosis in FAP. For this purpose 60 FAP families with 171 persons at risk were examined. By direct mutation analysis a presymptomatic diagnosis was achieved in 32% of the persons at risk; indirect genotype analysis was possible in 88% of the families in which more than one FAP patient was available. The ophthalmologic examination allowed a presymptomatic conclusion in 79% of the persons at risk. In no case there was a discrepancy in the results between the methods applied. The ophthalmologic presymptomatic test is useful especially in families where the index patients has a new mutation in the APC gene that has not been identified.

Adenomatous Polyposis Coli↗
PubMed1992

Lack of association between dopamine D1 and D2 receptor genes and bipolar affective disorder.

Fifty-six patients with bipolar affective disorder and 69 healthy control subjects were tested for association of restriction fragment length polymorphism alleles at the dopamine D1 and D2 receptor loci. No significant associations were found; thus, the hypothesis that a single mutant form of either receptor gene is responsible for the phenotype of patients with bipolar affective disorder was not supported.

Alleles↗
PubMed1991

Genotype-phenotype relationship in various degrees of arylsulfatase A deficiency.

Arylsulfatase A (ASA) is a lysosomal enzyme that hydrolyzes sulfatide. Absence of ASA activity leads to metachromatic leukodystrophy (MLD). The clinical outcome resulting from ASA deficiency is highly variable with respect to age of onset and symptoms. So far the causes for the variability are poorly understood. We have studied the relationship between the ASA genotype and the clinical phenotype. Fibroblasts from a total of 34 subjects with low ASA activity were examined with immunoblotting, a sensitive ASA assay, and the sulfatide loading test in order to characterize low ASA activity further. By these methods, three different classes of ASA deficiency can be defined: homozygosity for the pseudodeficiency allele (ASAp), compound heterozygosity for the ASAp and MLD (ASA-) alleles, and ASA-/ASA- genotypes. These genotypes exhibit different levels of ASA residual activity. Only ASA-/ASA- genotypes are associated with MLD. For diagnostic purposes, however, the differentiation of the various ASA genotypes is essential.

Adolescent↗
PubMed1991

Low arylsulphatase A activity and choreoathetotic syndrome in three siblings: differentiation of pseudodeficiency from metachromatic leukodystrophy.

We report on a family with a sibship of three children for whom the diagnosis of "an unusual form of metachromatic leukodystrophy (MLD)" had been suggested earlier. The patients had choreiform movements and dystonic posturing accompanied by dysarthria since childhood. The availability of the polymerase chain reaction enabled us to show that the three siblings have a pseudodeficiency genotype (ASAp/ASAp). There was no abnormal sulphatiduria, and we propose that the neurological disease and low arylsulphatase A activity are unrelated to one another in this family. A diagnosis of MLD carries very serious implications, and we recommend that gene amplification by polymerase chain reaction and hybridization with allele-specific oligonucleotide probes should be used to corroborate the diagnosis, especially when there is no abnormal sulphatiduria and when metachromatic material cannot be demonstrated in a sural nerve biopsy.

Adolescent↗
PubMed1991

Phenotypic consequences of low arylsulfatase A genotypes (ASAp/ASAp and ASA-/ASAp): does there exist an association with multiple sclerosis?

Arylsulfatase A (ASA) pseudodeficiency does per definitionem not lead to metachromatic leukodystrophy. It is conceivable, however, that it may contribute to the susceptibility for more common, multifactorial disorders of the nervous system. In order to examine whether there is an association with multiple sclerosis (MS), the most common demyelinating disease, we screened 160 MS patients for ASA activity and looked for pseudodeficiency genotypes using polymerase chain reaction. Four homozygotes for the ASA pseudodeficiency allele were found among the MS patients, but only one in the control sample. Further studies are necessary to validate whether ASA pseudodeficiency is associated with MS.

Alleles↗
PubMed1991

[Not Available].

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Genetics↗
PubMed1991

[Familial aggregation of psychiatric disorders and the consequences for the psychiatric diagnosis].

Schizophrenic and affective disorders, anxiety disorders, and alcoholism show familial aggregation; the impact of familial aggregation on the classification and etiology of psychiatric disorders is discussed. Ideal diagnostic schedules should a) identify conditions with a substantially increased familial risk and b) reach diagnostic homogeneity in multiplex families. A review of the literature shows a) that age at onset, long-term course and comorbidity modify familial risks and should therefore be given more attention in diagnostic schedules and b) that the heterogeneity of disorders in multiplex families draws the validity of currently used diagnostic schedules into question. Against this background the hypothesis of "unitary psychosis" is discussed.

Humans↗
PubMed1990

RFLP alleles at the tyrosine hydroxylase locus: no association found to affective disorders.

Affective disorders are usually referred to as being inherited multifactorially. The contribution of a gene locus in illnesses displaying multifactorial inheritance may be assessed by searching for associations of alleles to the illness. The tyrosine hydroxylase gene encodes the rate-limiting enzyme in the synthesis of catecholamines and might be a candidate for causing the manic-depressive phenotype. Therefore, we tested 88 patients with affective disorders and 99 healthy control persons for association of restriction fragment length polymorphism (RFLP) alleles at the tyrosine hydroxylase locus. The comparison of allele or genotype frequencies did not reveal any significant differences between the two groups.

Adolescent↗
PubMed1989

Pseudodeficiency of arylsulfatase A: a common genetic polymorphism with possible disease implications.

At the locus for arylsulfatase A (ASA) at least four to five alleles exist: besides the normal ASA+ and at least two to three deficiency alleles (ASA-), a pseudodeficiency allele, ASAp, is known. On SDS-PAGE the ASAp enzyme migrates slightly faster than ASA+. Treatment of extracts from cells with ASA+/ASA+, ASAp/ASAp, or ASA+/ASAp genotypes with endoglycosidase F leads to the same deglycosylated subunit pattern. Presumably the degree of glycosylation is lower in ASAp than in ASA+. In a large-scale screening project we determined a gene frequency of 7.3% for ASAp. Thus, the ASA locus is polymorphic. In seven families, ASAp showed a codominant mode of inheritance with ASA+. Homozygosity for ASAp has no obvious clinical consequences. In subjects with the compound genotype ASA-/ASAp, the residual enzyme activity may fall below a critical threshold, so that the substrate can no longer be hydrolyzed sufficiently. Since these compounds are not so rare (estimated frequency 0.073%), this mechanism could be of importance in neuropsychiatric disorders with late onset.

Alleles↗