( ( Children ( that ( ( have ( ( ( abnormally high ) ( serum levels ) ) ( of homocysteine ) ) ) ( , ( ( if untreated ) , ) ) ) ) ) ( often ( ( ( die ( of ( strokes ( and ( heart attacks ) ) ) ) ) ( before ( reaching adulthood ) ) ) . ) ) )
(ROOT (S (NP (NP (NNP Children)) (SBAR (WHNP (WDT that)) (S (VP (VBP have) (NP (NP (ADJP (RB abnormally) (JJ high)) (NN serum) (NNS levels)) (PP (IN of) (NP (NN homocysteine)))) (PRN (, ,) (SBAR (IN if) (FRAG (ADJP (JJ untreated)))) (, ,)))))) (ADVP (RB often)) (VP (VBP die) (PP (IN of) (NP (NNS strokes) (CC and) (NN heart) (NNS attacks))) (PP (IN before) (S (VP (VBG reaching) (NP (NN adulthood)))))) (. .)))
Children that have abnormally high serum levels of homocysteine, if untreated, often die of strokes and heart attacks before reaching adulthood.
(ROOT (S (NP (DT A) (NN heart) (NN attack) (CC or) (NN stroke)) (VP (VBZ is) (ADVP (RB often)) (NP (NP (DT a) (NN result)) (PP (IN of) (NP (JJ untreated) (NNS atherosclerosis))))) (. .)))