Syndactylies and Polydactylies: Embryological Overview and Suggested Classification

摘要: In 1978, Temtamy and McKusick classified isolated, non-syndromic polydactyly syndactyly, using a logical anatomical approach, into five distinct types for each group. Since then, there have been considerable advances in the molecular embryology of developing limb bud. These include proposal that retinoic acid and/or related retinoids are morphogens responsible morphogenetic gradient giving rise to anterior-posterior pattern formation bud, suggestion HOX4 complex other homeotic genes may also be involved patterning, greater understanding mechanisms such as programmed cell death shaping final hand foot. This paper briefly reviews development outlines 'end-organ responsiveness' limbs variety single-gene mutations. An alternative classification syndactylies polydactylies is suggested. It still too early match specific defects individual with precision, it obvious many important developmental remain identified; nevertheless, envisaged clues from embryological studies will become increasingly more useful.