MedGen

Brachydactyly type A2 is an autosomal dominant disorder characterized by malformations of the middle phalanx of the index finger and by anomalies of the second toe (summary by Su et al., 2011). [from OMIM]

The brachydactyly type C (BDC) phenotype includes brachymesophalangy of fingers 2, 3, and 5. The fourth finger is usually unaffected and thus appears as the longest finger of the hand. Shortening of metacarpal 1 and hyperphalangy in fingers 2 and 3 may occur and can be considered relatively characteristic signs. BDC can be highly variable, ranging from severely affected hands with very short fingers to mildly affected cases with only moderate brachydactyly, most often affecting the middle and proximal phalanges of fingers 2 and 3 (summary by Lehmann et al., 2006). [from OMIM]

Triangular shaped middle phalanx of the 2nd finger. A triangular or so called delta shaped phalanx is a typical result after a bracket epiphysis of the affected phalanx. [from HPO]