Fujiwara and colleagues [38] compared the effects on differential mRNA splicing of a splice donor site variant in TGFBR1 (c.973 + 1G > A) found in a Japanese patient with familial Loeys Dietz syndrome with the effects of the splice acceptor site variant (c.806-2A > C) discussed above. The gene discussed is TGFBR1; the disease is Loeys-Dietz syndrome.