High heritability of hallux valgus and lesser toe deformities in adult men and women.

OBJECTIVE: To estimate the heritability of 3 common disorders affecting the forefoot, i.e., hallux valgus, lesser toe deformities, and plantar forefoot soft tissue atrophy, in white adult men and women.

METHODS: Between 2002 and 2008, a trained examiner used a validated foot examination to document the presence of hallux valgus, lesser toe deformities, and plantar soft tissue atrophy in 2,446 adults from the Framingham Foot Study. Among these, 1,370 participants with an available pedigree structure were included. Heritability was estimated using pedigree structures by the Sequential Oligogenic Linkage Analysis Routines package. Results were adjusted for age, sex, and body mass index.

RESULTS: The mean age of the participants was 66 years (range 39-99 years) and 57% were women. The prevalence of hallux valgus, lesser toe deformities, and plantar soft tissue atrophy was 31%, 29.6%, and 28.4%, respectively. Significant heritability was found for hallux valgus (range 0.29-0.89, depending on age and sex) and lesser toe deformity (range 0.49-0.90, depending on age and sex). The heritability for lesser toe deformity in men and women ages >70 years was 0.65 (P = 9 × 10(-7)). Significant heritability was found for plantar soft tissue atrophy in men and women ages >70 years (H(2) = 0.37, P = 3.8 × 10(-3)).

CONCLUSION: To our knowledge, these are the first findings of heritability of foot disorders in humans, and they confirm the widely-held view that hallux valgus and lesser toe deformities are highly heritable in white men and women of European descent, underscoring the importance of future work to identify genetic determinants of the underlying genetic susceptibility to these common foot disorders.