Vol. 33, Nº 3

Radial polydactyly-revisiting its embryological, anatomical and etiological aspects

Nsari, R. M.; Kadir, F. A.

KEYWORDS: radial polydactyly, sonic hedgehog, chromosome 7q26.3 mutation.

ABSTRACT: Introduction: Radial polydactyly is a frequently encountered congenital anomaly. What is known less about this anomaly is its diverse etiology. In this situation, this article sheds more light on the embryology of the upper limb, the presentation, classification and a discussion on the varied etiology of radial polydactyly. Methodology: Review of various published literature from Scopus, PubMed central and Wiley’s online library. Results: Latest research proves that the various expressions of Sonic hedgehog (SHH) is responsible for this condition in addition to its varied etiology ranging from environmental factors, maternal diabetes and thalidomide embryopathy to chromosomal mutations. Pediatric surgeons have classified radial polydactyly into various subtypes in respect to its presentation and surgical outcomes. Conclusion: this paper is a concise review of radial polydactyly, exploring its anatomical, embryological and etiological aspects. It can be concluded that both genetic and environmental factors are culprits in the pathogenesis of radial polydactyly, but strong evidence pointing out the causal relationship between the environmental factors and Sonic Hedgehog expression is yet to be explored.