Table 2.

Extent of port-wine birthmark (PWB) in our patients with attributed Sturge-Weber syndrome (SWS) risk and in-sample SWS prevalence.

PWB Extent	PWB Pattern	Number of participants	In-Sample SWS Prevalence	SWS Risk % from Literature	Reference
1	Unilateral (less than complete hemifacial)	26	15 (58%)	19–10	(Tallman et al., 1991)
2	Central	2	1 (50%)	27	(Dutkiewicz et al., 2015)
3	Bilateral (excluding Hemifacial)	7	6 (86%)	32–40	(Tallman et al., 1991, Piram et al., 2012)
4	Hemifacial	13	10 (78%)	47	(Dutkiewicz et al., 2015)