Twin left circumflex arteries in a patient undergoing aortic valve replacement.

We present the case of a patient with severe symptomatic aortic valve (AV) stenosis in whom preoperative coronary angiography revealed two separate left circumflex (LCx) arteries, one arising from the left main coronary artery and the other from the right aortic sinus following thereafter a retroaortic course to the left. The pattern of LCx artery anatomy revealed was recognized as one of bilaterally arising twin LCx arteries that is a rare coronary anomaly with only 7 reported cases in the English literature. We discuss the importance of preoperative identification of this anomaly in patients undergoing AV surgery and describe simple clues in order to easily identify it.

Isolated single coronary artery with dual right coronary artery distribution. A rare anatomical variation.

We present the case of a 76-year-old patient in whom coronary angiography, performed due to non-ST-segment elevation myocardial infarction, revealed an isolated single coronary (SCA) artery with dual right coronary artery (RCA) distribution. One RCA arose from the mid segment of the left anterior descending (LAD) artery and followed a prepulmonic course to the right, while the other RCA arose as the terminal extension of the left circumflex artery beyond the crux cordis. This is the second reported case of the combination of these two variants of SCA and the first such case in which the LAD-derived RCA originated as a single branch. Furthermore, this is the first report presenting a sinus node artery with origin from an ectopic LAD-connected RCA. The clinical implications of this rare coronary artery pattern are discussed.

Geographical clustering of low density lipoprotein receptor gene mutations (C292X; Q363X; D365E & C660X) in Cyprus.

In Cyprus, no data are yet available on the frequencies of clinically diagnosed FH patients. Further, until now, familial hypercholesterolaemia in Cyprus had not been studied at the molecular level to determine the nature or frequency of LDLR gene mutations. Being a relatively homogeneous population, we anticipated that a few founder mutations would predominate on the island. In the present study, three previously identified LDLR gene mutations were found to cosegregate with high LDL cholesterol levels in 23 unrelated, clinically diagnosed families with FH. Geographical clustering of each of these LDLR gene mutations was indicated, a phenomenon arising from low migration rates and high inbreeding. The latter cultural practices account for the discovery of a homozygous FH sib pair whose parents are carriers of the same mutation. Microsatellite and intragenic haplotype analysis in this FH population, suggested that the families which shared the same LDLR gene mutation have a common origin. This is supported by their relative geographical distribution. Thirty young FH individuals were also offered presymptomatic diagnosis which should facilitate the prevention of premature coronary artery disease. Finally, results from this study support the suggestion that the formation of tendon xanthomata in FH patients may be under environmental influence. Hum Mutat 15:380, 2000.