The expression profiles of CHD-related genes  A. and B. Boxplots showing the expression levels for three categories of CHD-related genes in the brain (A) and heart (B) across different developmental time points. C. and D. Violin plot showing the difference between CHD-related genes and background genes in tissue-specificity (C) and time-specificity (D). The P values were obtained with Mann–Whitney U test. In all panels, CHD-related genes are classified into three categories: syndromic genes (red, n = 115), nonsyndromic genes (blue, n = 597), and genes reported in both syndromic and nonsyndromic CHD (orange, n = 414). A non-CHD gene set (n = 1124) was randomly selected as the background (gray). TPM, transcripts per million; PCW, post-conception week.