Yeast artificial chromosome cloning of the Xq13.3-q21.31 region and fine mapping of a deletion associated with choroideremia and nonspecific mental retardation. by van der Maarel, S, Scholten, I, Maat-Kievit, J, Huber, I, de Kok, Y, de Wijs, I, van de Pol, T, van Bokhoven, H, den Dunnen, J, van Ommen, G