From: Epidemiology of isolated preaxial polydactyly type I: Data from the Polish Registry of Congenital Malformations (PRCM)
Characteristic
Sporadic PPD1 N = 459
Thumb
Hallux
N = 435
P-value
N = 24
Unilateral
405
21
Left
157 (38.8%)
<0.0001
15 (71.4%)
0.08 (NS)
Right
248 (61.2%)
6 (28.6%)
Bilateral
18
3
Unknown
12
0