MONOZYGOTIC TWIN WITH POLYMICROGYRIA AND NORMAL COTWIN

Monozygous twinning has been associated with brain lesions such as hol oprosencephaly, hydranencephaly, multicystic encephalomalacia, and por encephaly. Polymicrogyria is rare but has been reported in autopsied c ases. We present a monozygotic twin with complicating twin-twin transf usion syndrome, the donor exhibiting normal psychomotor development an d the recipient psychomotor delay associated with the brain anomaly, p olymicrogyria. The brain anomaly might be due to blood pressure instab ility or a circulatory disturbance resulting from increased coagulabil ity due to polycythemia.