Each glucose isomer is subject to rotational isomerism. Due to chirality and possible double bond "cis-trans" isomerism, it has over 10 alternative stereoisomers. Ephedrine exhibits optical isomerism and has two chiral centres, giving rise to four stereoisomers. The ring-flip of substituted cyclohexanes constitutes another common form of conformational isomerism. Many of these molecules exhibit cis-trans isomerism. Asplenia is most often observed in patients with right atrial isomerism. The binding typically results in a change of conformational isomerism (conformation) of the target protein. Biliary atresia is not usually observed in patients with right atrial isomerism. He called this difference "geometrical isomerism". A common type of metastability is isomerism. The symmetry and isomerism of allenes has long fascinated organic chemists. This property gives rise to cis-trans isomerism. Clinical features and symptoms can vary dependent upon assignment of left versus right atrial isomerism. Such compounds give rise to linkage isomerism. Gene mutations that lead to atrial isomerism is a growing area of research.