TaqI polymorphism at the 3' end of the human pronatriodilatin gene (hPND)

Genetic decreases in atrial natriuretic peptide and salt-sensitive hypertension

To determine if defects in the atrial natriuretic peptide (ANP) system can cause hypertension, mice were generated with a disruption of the proANP gene. Homozygous mutants had no circulating or atrial ANP, and their blood pressures were elevated by 8 to 23 millimeters of mercury when they were fed standard (0.5 percent sodium chloride) and intermediate (2 percent sodium chloride) salt diets. On standard salt diets, heterozygotes had normal amounts of circulating ANP and normal blood pressures. However, on high (8 percent sodium chloride) salt diets they were hypertensive, with blood pressures elevated by 27 millimeters of mercury. These results demonstrate that genetically reduced production of ANP can lead to salt-sensitive hypertension.

Linkage mapping of the tumor necrosis factor receptor 2 (TNFR2) gene to 1p36.2 using the single-strand conformation polymorphism technique

We identified two informative polymorphisms in the transcribed 3' untranslated region of the tumor necrosis factor receptor 2 (TNFR2) gene using the polymerase chain reaction (PCR) with the single-strand conformation polymorphism (SSCP) technique. These polymorphisms demonstrated Mendelian inheritance and were useful for linkage analysis. TNFR2 was very closely linked to the pronatriodilatin gene (PND), and the TNFR2 SSCP polymorphisms were much more informative than the restriction fragment length polymorphisms currently available for the PND locus. In addition, we have demonstrated that genotyping could be performed with DNA obtained from paraffin-embedded tissue.

The CEPH consortium linkage map of human chromosome 1

This paper describes the Centre d'Etude du Polymorphisme Humain (CEPH) consortium linkage map of human chromosome 1. The map contains 101 loci defined by genotypes generated from CEPH family DNAs with 146 different contributions from 11 laboratories. A total of 58 loci are uniquely placed on the map with likelihood support of at least 1000:1. The map extends from loci in the terminal bands of both chromosome arms (locus D1Z2 in 1p36.3 and D1S68 in 1q44) and is anchored at the centromere by the D1Z5 alpha-satellite polymorphism. With the exception of a single locus, the remaining loci are arrayed on the fixed map in short intervals and their possible locations are indicated. Multipoint linkage analyses provided estimates that the male, female, and sex-averaged maps extend for 308, 478, and 390 cM, respectively. The sex-averaged map contains only four intervals greater than 15 cM, and the mean genetic distance between the 58 uniquely placed loci is 6.7 cM.

A clinically homogeneous group of families with facioscapulohumeral (Landouzy-Déjérine) muscular dystrophy: linkage analysis of six autosomes

Facioscapulohumeral muscular dystrophy (FSHMD) is a neuromuscular disorder characterized by autosomal dominant inheritance and clinical onset in the muscles of the face and shoulder girdle. Using a set of RFLP markers spaced at approximately 20 centimorgans, we have begun a systematic search for markers linked to the disease. A total of 81 RFLP loci on six autosomes (1, 2, 5, 7, 10, and 16) have been examined for linkage to FSHMD in 13 families. With the computer program CRI-MAP, two-point and multipoint analyses have not resulted in any LOD score indicative of linkage to FSHMD. However, these analyses have allowed us to exclude 909 centimorgans (sex average) of our genetic maps in intervals where the LOD score is less than -2.0. We estimate our data have excluded 23% of the human genome.

Molecular evaluation of abnormalities of the short arm of chromosome 1 in neuroblastoma

Cytogenetic analyses have documented the consistent deletion of part of the short arm of chromosome 1 in neuroblastoma cells suggesting the presence of a suppressor gene in this chromosomal region. To determine, the smallest region of deletion overlap at the molecular level on independently derived tumors and to define the location of the breakpoints more precisely, Southern analyses were performed on a somatic cell hybrid panel containing the normal and altered chromosomes 1 from seven neuroblastoma lines. By this method we were able to analyze a panel of 20 cloned sequences and two isozymes to determine the location of the breakpoints. Our findings indicate that the proximal breakpoints of chromosome 1 deletions ranged over a distance of more than 50 cM with the most distal deletion breakpoint occurring between MYCL1 and D1S57. In addition, using restriction fragment length polymorphisms, it was determined that in at least three of the five cell lines in which MYCL1 was deleted from a chromosome 1, the gene was translocated to another chromosome thus retaining the diploid complement. We propose that the neuroblastoma susceptibility gene is located distal to MYCL1 and that there is another gene which is linked to MYCL1 that may be involved in this neoplasm.

Linkage analysis in Marfan syndrome

We have analysed 40 marker loci on 13 chromosomes for linkage with Marfan syndrome. None of the loci was linked to the Marfan syndrome locus at theta = 0.00. This study provides a basis for an exclusion map and for further collaboration in mapping of the locus.

Twenty-eight loci form a continuous linkage map of markers for human chromosome 1

We have used a combination of 30 serological, protein electromorphic, and DNA markers defining 28 loci to construct a linkage map of chromosome 1. These markers form a continuous linkage group of 320 cM in males and 608 cM in females; female genetic distances were on average twofold higher than those of males across the map. Among the DNA markers are 10 highly polymorphic markers reflecting loci that contain a variable number of tandem repeats, well distributed over the length of the chromosome, that will be highly efficient anchor points for application of this map to studies of human genetic disease.

NsiI and ScaI restriction fragment length polymorphisms at the atrial natriuretic peptides (ANP) gene locus

The authors report on two new restriction fragment length polymorphisms at the human atrial natriuretic peptide gene locus, detected in three families with restriction endonucleases ScaI and NsiI.