ACTL6A and neural tube defect: For genes that function more specifically in chromatin remodeling (ACTL6A, CECR2, SMARCA4, SMARCC1 and ATRX) there were 22 PDRVs in 355 NTD cases, which was slightly but significantly more than in controls (5/225; P = 0.041, two-sided Fisher’s exact test).