Biallelic loss-of-function of WNT10B causes Split-Hand/Foot Malformation 6 (SHFM6, MIM #225300). This malformation is characterized by central ray defects, mostly the absence of 2nd, 3rd and/or 4th fingers/toes. Some patients present a complex form of SHFM, with syndactyly or supernumerary bone. Feet are often more affected than hands, with typical split feet (only 2 toes present, the 1st and the 5th). No other malformation has been identified in this syndrome.
The prevalence of malformation due to mutations in WNT10Bis unknown, but it represents a very small part of the SHFM occurring every 1/18000 birth. Typical and severe form of this syndrome is autosomal recessive, with 25% risk of recurrence in siblings, however heterozygous patients may exhibit mild features of SHFM spectrum, like 3th and 4th rays syndactyly. Heterozygous variants in WNT10B gene are also associated with teeth anomalies such as agenesis, cone-shaped, and small teeth (MIM #617073). So far, no tooth anomaly has been reported in SHFM6 families, neither in the homozygous patients nor in their heterozygous relatives.
WNT10B