Fetal polysplenia and situs inversus in siblings. Case reports

Heterotaxy syndromes, otherwise laterality defects, are variations from anatomic left-right asymmetry. Situs inversus is the complete reversal of the normal situs, still situs ambiguus is the randomisation of the normal organ position. Situs ambiguus may be manifested as asplenia or polysplenia syndrome. Normal situs and both types of the heterotaxy syndromes may appear among some affected families, whereas the different situs are rarely expressed in the same family. We describe an autosomal-recessive inherited familial heterotaxy syndrome with two affected siblings - one of whom has situs inversus, and the other with polysplenia syndrome. The polysplenia syndrome was diagnosed by fetal echocardiography. Since the chromosomal or molecular diagnosis of laterality defects are accessible only in X-linked heterotaxy syndromes, the fetal echocardiography is the earliest available diagnostic method in this field. Therefore, fetal echocardiography has great importance for affected families.