Complex sentence: Polysplenia sometimes occurs alone, but it is often accompanied by other developmental abnormalities such as intestinal malrotation or biliary atresia, or cardiac abnormalities, such as dextrocardia.
Split into simpler sentences: Polysplenia sometimes occurs alone, but it is often accompanied by other developmental abnormalities. Conditions associated with polysplenia include gastrointestinal abnormalities, such as intestinal malrotation or biliary atresia, as well as cardiac abnormalities, such as dextrocardia.