Because of the location of this frameshift variant within the TFGBR2 locus, it is expected that transcripts derived from the variant TGFBR2 allele in our patients would undergo nonsense-mediated decay, resulting in decreased TGFBR2 protein and reduced TGFβ signaling, and thus potentially a different mechanistic impact to those variants seen in Loeys-Dietz syndrome. Here, TGFB1 is linked to Loeys-Dietz syndrome.