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Summary: Williams–Beuren syndrome (WBS) (OMIM# 194050) is a rare, most often sporadic, genetic disease caused by a chromosomal microdeletion at locus 7q11.23 involving 28 genes. Among these, the elastin gene codes for the essential component of the arterial extracellular matrix. Developmental disorders usually associate an atypical face, cardiovascular malformations (most often supravalvular aortic stenosis and/or pulmonary artery stenosis) and a unique neuropsychological profile. This profile is defined by moderate mental retardation, relatively well-preserved language skills, visuospatial deficits and hypersociability. Other less known or rarer features, such as neonatal hypercalcemia, nutrition problems in infancy, ophthalmological anomalies, hypothyroidism, growth retardation, joint disturbances, dental anomalies and hypertension arising in adolescence or adulthood, should be treated. The aim of this paper is to summarize the major points of WBS regarding: (i) the different genes involved in the deletion and their function, especially the elastin gene and recent reports of rare forms of partial WBS or of an opposite syndrome stemming from a microduplication of the 7q11.23 locus, (ii) the clinical features in children and adults with a focus on cardiovascular injury, and (iii) the specific neuropsychological profile of people with WBS through its characteristics, the brain structures involved, and learning. [Copyright &y& Elsevier]

Elastin, the main component of elastic fibers, is synthesized only in early life and provides the blood vessels with their elastic properties. With aging, elastin is progressively degraded, leading to arterial enlargement, stiffening, and dysfunction. Also, elastin is a key regulator of vascular smooth muscle cell proliferation and migration during development since heterozygous mutations in its gene (Eln) are responsible for a severe obstructive vascular disease, supravalvular aortic stenosis, isolated or associated to Williams syndrome. Here, we have studied whether early elastin synthesis could also influence the aging processes, by comparing the structure and function of ascending aorta from 6- and 24-month-old Eln+/- and Eln+/+ mice. Eln+/- animals have high blood pressure and arteries with smaller diameters and more rigid walls containing additional although thinner elastic lamellas. Nevertheless, longevity of these animals is unaffected. In young adult Eln+/- mice, some features resemble vascular aging of wild-type animals: cardiac hypertrophy, loss of elasticity of the arterial wall through enhanced fragmentation of the elastic fibers, and extracellular matrix accumulation in the aortic wall, in particular in the intima. In Eln+/- animals, we also observed an age-dependent alteration of endothelial vasorelaxant function. On the contrary, Eln+/- mice were protected from several classical consequences of aging visible in aged Eln+/+ mice, such as arterial wall thickening and alteration of alpha(1)-adrenoceptor-mediated vasoconstriction. Our results suggest that early elastin expression and organization modify arterial aging through their impact on both vascular cell physiology and structure and mechanics of blood vessels. [ABSTRACT FROM AUTHOR]