Abuuri nooc ka sii adag weedhan Billy wuxuu ku dhashay xanuunka wadnaha ee loo yaqaano Tetralogy of Fallot (TOF), kaas oo markii ugu horeysay ay ogaatay kalkaalisada caafimaad markuu jiray saddex saacadood.
Dabcan, nooc ka sii adag xukunka ayaa ah "Billy wuxuu ku dhashay xaalad wadneed oo loo yaqaan 'tetralogy of Fallot (TOF) ', taas oo u baahan doonta inuu ku lug yeesho ugu yaraan seddex qalliin oo wadne furan ah noloshiisa, mid ka mid ahna waxaa la sameeyay markii uu saddex maalmood jiray. "