<?php
use Doctrine\ORM\Mapping AS ORM;
namespace Shopware\Models\Article;

/**
 * @ORM\MappedSuperclass
 */
class MappedSuperclassBase
{
  /**
   * @ORM\Column(type="integer", nullable=true)
   */
  private $mapped1;

  /**
   * @ORM\Column(type="string", nullable=true)
   */
  private $mapped2;
}

<?php
use Doctrine\ORM\Mapping AS ORM;

/**
 * @ORM\Entity
 */
class EntitySubClass extends MappedSuperclassBase
{
  /**
   * @ORM\Column(type="string", nullable=true)
   */
  private $name;
}