Classification and identification of inherited brachydactylies.

A search for patterns of malformation in the brachydactylies has resulted in new ways to identify the different types. Type A-1 can be characterised by a proportionate reduction of the middle phalanges. Type B is thought to be an amputation-like defect. In type C the fourth middle phalanx is usually the longest, and type E (Riccardi and Holmes, 1974) is characterised by short metacarpals and short distal phalanges. Short stature is usually present in type A-1 and type E brachydactyly (Riccardi and Holmes, 1974) and it may be present in some individuals with brachydactyly C. As short children have short hands, it is possible that in patients with very mild expressions of brachydactyly the cause of the short stature may be overlooked. It is suggested that in every child with proportionate short stature the hands should be carefully examined. If the hands are disproportionately short, if any distal creases are missing, if there is a shortening, however mild, of any finger, if any metacarpals are short, then it is important to have ϰ-rays to look for brachydactyly A-1, C, or E. Much information is still needed. It is important in future reports to have skeletal surveys, pattern profile analyses, and to note the height of children with brachydactyly C. Most interesting of all will be when fetal limbs of each type become available for study.