The phenotypes of combined LWD and achondroplasia or hypochondroplasia appeared to be less than additive, suggesting that SHOX and FGFR3 act on overlapping pathways of bone growth and development.
A regulation that occurs mainly in the mesomelic segments, a region where SHOX is known to be strongly expressed, offers a possible explanation for the phenotypes seen in patients with FGFR3 (e.g. achondroplasia) and SHOX defects (e.g.Léri-Weill dyschondrosteosis).