Table 2 Heritability estimates for radiographic phenotypes, after adjustment for age, gender and body mass index

First IP count

0.63 (0.15)

0.00004

0.70 (0.15)

0.00001

DIP count

0.36 (0.1643)

0.02

0.36 (0.17)

0.019

PIP count^a

0.30 (0.16)

0.03

0.28 (0.17)

0.04

DIP/IP/PIP count^a

0.42 (0.16)

0.004

0.41 (0.16)

0.006

CMC count

0.38 (0.17)

0.01

0.46 (0.17)

0.005

Total count^a

0.38 (0.16)

0.008

0.38 (0.16)

0.01

First IP score^a

0.84 (0.14)

0.0000001

0.89 (0.14)

2.70 × 10^-9

DIP score^a

0.18 (0.16)

0.12

0.16 (0.17)

0.17

PIP score^a

0.16 (0.15)

0.15

0.14 (0.16)

0.18

DIP/IP/PIP score^a

0.33 (0.16)

0.02

0.33 (0.16)

0.02

CMC score

0.53 (0.16)

0.0006

0.63 (0.16)

0.0001

Total score^a

0.35 (0.16)

0.01

0.36 (0.16)

0.01

Subchondral cysts^a

0.17 (0.15)

0.13

0.13 (0.16)

0.20

Joint subluxation^a

0.27 (0.17)

0.06

0.19 (0.19)

0.15

Joint space narrowing^a

0.24 (0.16)

0.06

0.18 (0.17)

0.14

Subchondral sclerosis^a

0.17 (0.16)

0.14

0.15 (0.17)

0.18

Erosions^a

0.12 (0.14)

0.20

0.13 (0.15)

0.20

Joint deformity^a

0.31 (0.20)

0.06

0.15 (0.20)

0.24

Heberden's nodes

0.36 (0.22)

0.07

0.21 (0.23)

0.19