Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Congenital aortic Regurgitation: Natural history and management

AbstractObjectives and Background. Congenital aortic regurgitation is rare as an isolated lesion. We describe seven children with no physical features of the Marfan syndrome in the patients or their families and no cardiac lesions who had congenital valvular aortic regurgitation.Methods. From 1954 to the present, seven children with auscultatory and physiologic characteristics of aortic regurgitation were evaluated for a total of 108 patient-years. We report on their natural history, clinical and laboratory findings, management and outcome.Results. In five of the seven children congenital aortic regurgitation was diagnosed in infancy. In four, progressive severity of the regurgitation led to valve replacement at age 3, 10, 15 and 20 years, respectively, and to resection of an aneurysm of the ascending aorta in the 10-year old patient. Two patients had cystic medial necrosis on aortic biopsy. One of these patients died after reoperation for dissecting aneurysm of the thoracic aorta at 22 years of age; the other died after dissection and rupture of the ascending aorta at age 25 years. After obstructing pannus developed, the 3-year old patient underwent replacement of the St. Jude valve at age 10 years. The other three patients were asymptomatic at last follow-up at age 8, 10 and 20 years, respectively.Conclusions. Supportive management is recommended until it becomes necessary to intervene surgically when regurgitation becomes severe. The need for surgical treatment is indicated by the appearance of a diastolic thrill, left ventricular strain on the electrocardiogram or other evidence of left ventricular dysfunction on the echocardiogram or exercise stress testing by treadmill or radionuclide cineangiocardiography. Close follow-up of these patients is important to detect progression of aortic regurgitation, especially in the presence of cystic medial necrosis