Palm Index Hypoplasia Illustrating the Concept of Developmental Field (DF)
Please click to enlarge.
Note what signs you see.
I (W. Wertelecki, M.D.) see a palm with a single transverse palmar flexion crease (simian or Sm) and a shortened bent index finger (brachydactyly, clinodactyly).
CONTRARY TO DARWIN’S POSTULATES, FUNCTION PRECEDES STRUCTURE (in Genetics)
PERSPECTIVE: The intent of showing this image is to refer to the concept of developmental field (DF) proposed by J. Opitz in 1992. The concept DF is elaborated upon elsewhere. This example suggests that the DF for fingers 3-4-5 is distinct from the DF for fingers 1-2. Functionally the digital DF 1-2 (inclusive of fingers and toes) is distinct from the DF digital 3-5. These two DF can be also referred to as pre-axial or radial and post-axial or ulnar. The interpretation of the presence of Sm is more nebulous.