SNP Shot: Genomic Insights

Tarsal-carpal coalition syndrome is a rare, genetic condition affecting primarily the hands and feet. It involves the fusion of carpal bones in the wrist and tarsal bones in the ankle. This fusion leads to stiffness and limited movement in the hands and feet. Symptoms can appear in infancy and typically worsen over time, with the severity varying from person to person, even within the same family.

A related feature of this condition is symphalangism, where the bones within the fingers and toes fuse together. This results in stiff, inflexible digits, starting with the pinky fingers and toes. Initially, the joints at the base of these digits fuse, and then the fusion may extend to other joints along the digit. This process can progress to affect the ring, middle, and index fingers and their corresponding toes. The thumb and big toe are usually spared. As the condition progresses, affected individuals experience increased difficulty in making a fist and may experience pain and difficulty walking. Less frequently, fusion can occur at the elbow joint between the upper and lower arm bones (humeroradial fusion). Other uncommon features associated with tarsal-carpal coalition syndrome can include short stature or hearing loss.

Inheritance:

Tarsal-carpal coalition syndrome follows an autosomal dominant inheritance pattern. This means that only one copy of the mutated gene is needed in each cell to cause the condition.