Congenital three generation wide familial non-syndromic polydactyly

Abstract

Polydactyly is typically observed as isolated and sporadic occurrences, although familial cases do exist, albeit with lower frequency, manifesting in various inheritance patterns. In around 30% of polydactyly cases, there exists a familial history, suggesting the probable involvement of a single gene. Given its potential for hereditary transmission, thorough investigation of the patients' parents, first-degree relatives, grandparents, and even great-grandparents for similar disorders becomes imperative. In our clinic, we conducted an analysis focusing on patients presenting with foot polydactyly, along with occurrences of polydactyly among their first- and second-degree relatives spanning two to three generations of family history. The study encompassed three patients and their respective families, including a pair of siblings. We speculate that the inheritance type in our cases was autosomal dominant. Among our patients, one presented with central polydactyly, while the remaining patients and all familial cases displayed postaxial polydactyly. In terms of morphologic classification, one patient had a Y-shaped metatarsal, another had a T-shaped metatarsal, and the third patient exhibited a duplicated ray-shaped anomaly. In our review of the literature, we haven't come across a case spanning three generations like the ones we encountered. Additionally, the presence of a transverse accessory extensor tendon between both extensor tendons in cases with T- and Y-shaped metatarsals intrigued us from an anatomical perspective. Our goal is to present these rare cases of congenital familial polydactyly spanning three generations, highlighting the anatomical variations observed and aiming to contribute to the existing body of literature on the subject.