Tangier disease (TD) was first discovered nearly 40 years ago in two siblings living on Tangier Island. This autosomal co-dominant condition is characterized in the homozygous state by the absence of HDL-cholesterol (HDL-C) from plasma, hepatosplenomegaly, peripheral neuropathy and frequently premature coronary artery disease (CAD). In heterozygotes, HDL-C levels are about one-half those of normal individuals. Impaired cholesterol efflux from macrophages leads to the presence of foam cells throughout the body, which may explain the increased risk of coronary heart disease in some TD families. We report here refining of our previous linkage of the TD gene to a 1-cM region between markers D9S271 and D9S1866 on chromosome 9q31, in which we found the gene encoding human ATP cassette-binding transporter 1 (ABC1). We also found a change in ABC1 expression level on cholesterol loading of phorbol ester-treated THP1 macrophages, substantiating the role of ABC1 in cholesterol efflux. We cloned the full-length cDNA and sequenced the gene in two unrelated families with four TD homozygotes. In the first pedigree, a 1-bp deletion in exon 13, resulting in truncation of the predicted protein to approximately one-fourth of its normal size, co-segregated with the disease phenotype. An in-frame insertion-deletion in exon 12 was found in the second family. Our findings indicate that defects in ABC1, encoding a member of the ABC transporter superfamily, are the cause of TD.

We present an analysis of 400 intralobar and 133 extralobar sequestrations, six cases presenting intra-and extralobar sequestration simultaneously, five sequestrations of one whole lung, and two bilateral intralobar sequestrations.This anomaly comprises 0 15-6 4% of all congenital pulmonary malformations. Usually the posterior basal segment is affected.The aberrant artery in intralobar sequestration originated in 74% of all cases from the thoracic aorta, and in 14*8% there was more than one anomalous artery. The mean diameter of the aberrant arteries was 643-6 6 mm. Usually arteries with predominantly elastic fibres were found. Arteriosclerotic changes were common, even in children.

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With increasing knowledge about the causal role of genetic defects in clinical diseases the necessity is apparent to have procedures for rapid diagnosis of point mutations. We developed a PCR-based technique, whereby both normal and mutant alleles can be amplified in the same reaction tube, using different length allele-specific primers. Furthermore the allele-specific primers introduce additional deliberate differences into the allelic PCR-products that drastically reduce crossreactions in subsequent cycles. This mutagenesis separates the amplification reactions of the alleles performed in the same tube. Subsequent identification of the PCR-products is done by gel electrophoresis and shows at least one of the two allelic products. Therefore, in addition to simple handling, MS-PCR provides a within-assay quality control for the exclusion of false negative results. The feasibility of this technique has been tested using six different mutations. The high sensitivity of MS-PCR also allows screening for mutation carriers in pooled DNA samples.

Background — Congenital long QT syndrome (LQTS), a cardiac ion channel disease, is an important cause of sudden cardiac death. Prolongation of the QT interval has recently been associated with sudden infant death syndrome, which is the leading cause of death among infants between 1 week and 1 year of age. Available data suggest that early onset of congenital LQTS may contribute to premature sudden cardiac death in otherwise healthy infants. Methods and Results — In an infant who died suddenly at the age of 9 weeks, we performed mutation screening in all known LQTS genes. In the surface ECG soon after birth, a prolonged QTc interval (600 ms 1/2 ) and polymorphic ventricular tachyarrhythmias were documented. Mutational analysis identified a missense mutation (Ala1330Pro) in the cardiac sodium channel gene SCN5A , which was absent in both parents. Subsequent genetic testing confirmed paternity, thus suggesting a de novo origin. Voltage-clamp recordings of recombinant A1330P mutant channel expressed in HEK-293 cells showed a positive shift in voltage dependence of inactivation, a slowing of the time course of inactivation, and a faster recovery from inactivation. Conclusions — In this study, we report a de novo mutation in the sodium channel gene SCN5A , which is associated with sudden infant death. The altered functional characteristics of the mutant channel was different from previously reported LQTS3 mutants and caused a delay in final repolarization. Even in families without a history of LQTS, de novo mutations in cardiac ion channel genes may lead to sudden cardiac death in very young infants.

Tangier disease is characterized by low serum high density lipoproteins and a biochemical defect in the cellular efflux of lipids to high density lipoproteins. ABC1, a member of the ATP-binding cassette family, recently has been identified as the defective gene in Tangier

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