The MSX1 Allele 4 Homozygous Child Exposed to Smoking at Periconception Is Most Sensitive in Developing Nonsyndromic Orofacial Clefts - van den Boogaard, M J; de Costa, D; Krapels, I P; Liu, F; van Duijn, C; Sinke, R J; Lindhout, D; Steegers-Theunissen, R P (Hum Genet, 2008)