Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement
Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.
Hallux Valgus and Pes Cavus Are Highly Heritable in Older Men and Women: The Framingham Foot Study.
Hannan4, Marian T., Hsu3, Yi-Hsiang, Cupples2, L. Adrienne, Jordan1, Joanne M.
Foot disorders are common among adults, affecting 2060% of adults and often linked to mobility limitations. Although genetics are commonly suspected in foot disorders, only one family aggregation study has been done, reporting that 90% of 350 participants with hallux valgus had a family history, and inheritance may be an autosomal dominant transmission. To our knowledge, no other studies have examined the association between foot disorders and genetics in humans. We have the unique opportunity to link data that we have collected on specific foot disorders to a wealth of genetic data in the community-based Framingham Study. Our aim was to evaluate the possible heritability of two common foot disorders, using the pedigree structure in the Framingham Study.
The Framingham Foot Study (n=2179) was designed to examine common foot disorders and functional limitations. A trained examiner used a validated foot exam to assess 20 foot disorders in 2179 participants between 20022005. Of participants, 959 men and 1220 women had been genotyped. We estimated overall, sex-specific and age (< 60, 60+y) heritability of hallux valgus and pes cavus (our most common and least common foot disorders) in the Framingham participants. Hallux valgus (present/absent) was defined as the angular deviation of the hallux with respect to the first metatarsal toward the lesser toes at >=15°. Pes cavus was defined using a digital recording of foot pressure while walking (MatScan pedobarographic device, Tekscan, Inc. Boston MA), that allowed calculation of the ratio of arch width (medial to lateral, to nearest 0.01 cm) to heel width. Pes cavus was defined as either foot as having a weight-bearing arch width=0, regardless of heel width. We estimated heritability of hallux valgus and pes cavus by the threshold model of a standard quantitative genetic variance-components model implemented in the Sequential Oligogenic Linkage Analysis Routines (SOLAR) package.
Mean age was 66y (range 3999y); 57% were female. The prevalence of hallux valgus (HV) was 31% (675 hallux valgus cases with available pedigree structure). The overall HV heritability was 0.39 for women and 0.38 for men. For persons aged < 60y, the HV heritability was 0.89. The prevalence of pes cavus (PC) was only 7% (154 cases with available pedigree structure have pes cavus). The PC heritability was 0.68 for women and 0.20 for men. For individuals < 60y of age, the PC heritability was 0.99 for women and 0.63 for men. Thus, hallux valgus and pes cavus are highly heritable, especially for younger adults.
This study breaks new ground in an area that has received very little attention, yet is critically important to public health. Our study documented for the first time, the high heritability (strongly suspected by many) of two specific foot disorders phenotypes. Foot disorders are common and it is important to identify persons at high risk, as effective interventions exist and may also be targeted to individuals to lessen the impact of foot disorders or prevent development. Genome-wide association analyses are planned to identify potential genetic determinants for these common foot disorders.
To cite this abstract, please use the following information:
Hannan, Marian T., Hsu, Yi-Hsiang, Cupples, L. Adrienne, Jordan, Joanne M.; Hallux Valgus and Pes Cavus Are Highly Heritable in Older Men and Women: The Framingham Foot Study. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :1329