Asplenia and polysplenia syndromes with abnormalities of lateralisation in a sibship

In the family presented here the first child had asplenia syndrome with cor biloculare' transposition of the great vessels, pulmonary stenosis, and anomalous pulmonary venous drainage. Another sib had situs inversus with polysplenia syndrome, including very similar cardiovascular defects and biliary atresia. The possibility that these two syndromes, namely asplenia and polysplenia, are different manifestations of a similar defect in the normal asymmetrical development of internal organs is discussed.