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Biomedical subjects

P Propping

Publications and source records attributed to P Propping.

At least 163 records · Page 9Linked to original sources

No evidence of association between dopamine D4 receptor variants and bipolar affective disorder.

Disturbance in the dopamine neurotransmitter system has been implicated in the pathogenesis of affective disorder. In this study, we examine the possibility that functional variants of the recently cloned dopamine D4 receptor gene contribute to the genetic component of manic depression. The polymorphism, a 48 bp tandem repeat coding for part of the third cytoplasmic loop, was detected using a PCR based method. In a first sample of 57 patients and 59 controls, we found allele 7 to be in excess in the patients. In contrast, allele 3 was less frequent in patients. A second, larger sample of 90 patients and 91 controls was utilized to test these hypotheses. Data from the two samples were then pooled together for further analyses. We calculated the power of our samples, and if the frequency of 7 repeat allele obtained from sample 1 is true, i.e., 25% (28/114) for patients and 14% (16/118) for controls, then the power of the combined sample is 62% at 5% (two-tailed) significance level. However, both observations were not replicated; we therefore conclude that variations in this repeat at the DRD4 gene do not contribute to the genetic component of manic depression.

Alleles↗

Frequency of common and novel inactivating APC mutations in 202 families with familial adenomatous polyposis.

In the course of presymptomatic diagnosis in families with familial adenomatous polyposis (FAP) we screened 202 unrelated patients for mutations in the APC gene. Germ-line mutations were identified in 20.8% of the index patients by a single step screening procedure based on heteroduplex analysis of a PCR product encompassing codons 1027-1384 of the APC gene. The most common mutations in our sample were a 5 bp deletion at codon 1309 in 9% of the families, a 5 bp deletion at codon 1061 in 5% and a 4 bp deletion at codon 1068 in 2.5% of the families. In addition, 11 novel mutations localized within the exons 11-15 of the APC gene were identified by the heteroduplex or SSCP methods.

Adenomatous Polyposis Coli↗

[Progress in molecular genetic diagnosis].

The most frequent monogenically inherited disorders and an increasing number of rare monogenic disorders are already mapped, and the genetic defect leading to the disease was in part of the genes identified. Thus, detection of carriers of different disorders becomes possible by indirect or direct genotype analysis. The introduction of new analytical methods, e.g. polymerase chain reaction (PCR) and microsatellites permits a faster and safer diagnosis and in addition, a smaller amount of biological material is necessary. The identification of genes that are mutated in different inherited malignancies improves cancer prevention strategies in these families. A new class of gene defects--the "dynamic" mutations--consisting in the expansion of trinucleotid repeats within disease genes was identified in several disorders (e.g. fragile X-Syndrome, Huntington's disease, myotonic dystrophy); expanding trinucleotid repeats may explain some problems regarding the mode of inheritance and anticipation observed in these disorders, that were so far not understood. For studies of complex genetic disorders several new approaches were developed, however, so far they cannot be used for diagnostic purposes.

DNA Mutational Analysis↗

ADULT-syndrome: an autosomal-dominant disorder with pigment anomalies, ectrodactyly, nail dysplasia, and hypodontia.

We describe a family with at least seven living persons who are affected by an hitherto undescribed autosomal-dominant syndrome with variable expression, bearing close resemblance to the EEC syndrome and related disorders. The main manifestations are hypodontia and/or early loss of permanent teeth, ectrodactyly, obstruction of lacrimal ducts, onychodysplasia, and excessive freckling. We propose the acronym ADULT (acro-dermato-ungual-lacrimal-tooth)-syndrome for this condition.

Abnormalities, Multiple↗

Mapping of the gene for X-chromosomal split-hand/split-foot anomaly to Xq26-q26.1.

A large inbred kindred from Pakistan in which an isolated type of split-hand/split-foot anomaly is transmitted as an X-chromosomal trait has previously been described. An X/autosomal translocation and an X-chromosomal rearrangement have been excluded by cytogenetic studies. In order to map the gene responsible for this disorder, linkage analysis has been performed by using 14 highly polymorphic DNA markers distributed over the whole X chromosome. Two-point linkage analysis between the disease locus and X-chromosomal marker loci gives maximal lod scores at theta = 0.00 with the loci DXS294 (Zmax = 5.13) and HPRT (Zmax = 4.43), respectively, suggesting that the gene for the X-chromosomal split-hand/split-foot anomaly is localized at Xq26-q26.1.

Chromosome Mapping↗

Retrospective study of the parental origin of the extra chromosome in trisomy 18 (Edwards syndrome).

The parental origin of the extra chromosome in trisomy 18 was traced in 30 informative families using highly polymorphic (CA) repeats mapped on the long arm of chromosome 18. Proband DNA was recovered from slides of chromosome preparations in 28 cases and from paraffin-embedded tissues in two cases. The extra chromosome was found to be of maternal origin in 26 cases (86.7%), and paternal origin in 4 cases (13.3%).

Adult↗

The use of microsatellites in zygosity diagnosis of twins.

Although numerous genetic and anthropological markers are available for determining zygosity of twins, there is still a need for a more practical and informative method in zygosity diagnosis. Dinucleotide repeats or other short repeats (microsatellites) are highly variable between individuals and offer a simple, fast, cheap, and exact approach for zygosity determination. The feasibility of a set of microsatellites to be used for this purpose is demonstrated.

Alleles↗

Familial cosegregation of affective disorder and Hailey-Hailey disease.

We report on a family with co-occurrence of affective disorder and Hailey-Hailey disease in two brothers and the mother. The putative chromosomal locus of Hailey-Hailey disease, which is a rare dominantly inherited dermatosis, may be a promising candidate region for genetic studies in affective disorder.

Bipolar Disorder↗

Compound heterozygosity for metachromatic leukodystrophy and arylsulfatase A pseudodeficiency alleles is not associated with progressive neurological disease.

Several allelic mutations at the arylsulfatase A (ASA) locus cause substantial deficiencies of this lysosomal enzyme. Depending on the genetically determined degree of the deficiency, the clinical outcome may be very different--either metachromatic leukodystrophy (MLD), a lethal lysosomal storage disorder affecting the nervous system, or, more frequently, the so-called pseudodeficiency (PD), which has no apparent clinical consequence. Because of compound heterozygosity for MLD and PD, 1/1,000 individuals in the population have low residual enzyme activities, which are intermediate between those of MLD patients and those of PD homozygous normal individuals. In order to assess whether PD/MLD compound heterozygotes bear a health risk, we examined clinically and biochemically 16 individuals with this genotype. Of these subjects, two had neurological symptoms and two showed lesions, without clinical symptoms, in magnetic resonance imaging of the brain. None of these symptoms was progressive, nor did they resemble those of MLD. Nerve conduction velocities were normal in these probands, and they secreted only low amounts of sulfatide in the urine. We conclude that the observed neurological symptoms are unrelated to the ASA genotype and that PD/MLD compound heterozygotes are not at an increased risk for developing progressive nervous system diseases.

Adolescent↗