• NURUDEEN ABIOLA OPADOKUN
• ADEOYE OYEYEMI FATIMOH

ABSTRACT Synpolydactyly also called Polysyndactyly is a birth defect that occurs in the fingers or toes to cause the formation of an extra digit or extra toe that are web-like or fused to the other digit. We are making an unusual presentation of a polysyndactyly of left thumb of a cadaver case that was found during the process of dissection. It is a genetically acquired anomaly that occurs in the form of polysyndactyly mainly an autosomal dominant one. The exact mutations that cause the development of polysyndactyly differ between the type of the condition and in different families. But most of them are caused genetically by a shift in the genetic factors concerning the signaling molecule belonging to the Sonic Hedgehog (SHH). Mostly, mutations are present in the zone of polarizing activity regulatory sequence or ZRS which regulates expression of SHH in the developing limbs. Numerous instances of polysyndactyly are findings of duplications involving the ZRS or its neighbouring pre-ZRS zone. In this case report of a Weird and rare case of unilateral thumb synpolydacty in an adult male cadaver is presented. These extreme incidences emphasize the necessity of intensive anatomical studies on developing our understanding of congenital limb anomalies and provide informative facts on its scope. Synpolydactyly which is also known as Polysyndactyly is a congenital anomaly which affect the fingers or toe resulting into a formation of an extra finger or toe that are webbed or fused together with the adjacent digit. We present a rare case of a polysyndactyly on left thumb of a cadaver discovered during dissection. Polysyndactyly is mostly an inherited autosomal dominant anomaly. The specific mutations leading to polysyndactyly are varied between types of the condition and different families. However, the etiology of most of the cases are due to changes in genetic elements affecting the signaling molecule Sonic Hedgehog (SHH). Primarily, mutations are found in the zone of polarizing activity regulatory sequence, or ZRS, that controls the expression of SHH in developing limbs. Many cases of polysyndactyly are the result of duplications of the ZRS or the nearby pre-ZRS region. An unusual instance of unilateral thumb synpolydactyly in an adult male cadaver is highlighted in this case report. These exceptional cases highlight the need of thorough anatomical research in expanding our knowledge of congenital limb abnormalities and offer insightful information on their range.

Sonic Hedgehog (SHH),zone of polarizing activity regulatory sequence or ZRS

"POLYSYNDACTYLY OF UNILATERAL THUMB OF THE LEFT HAND- A CADAVERIC CASE REPORT.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.12, Issue 9, page no.c530-c535, September-2025, Available :http://www.jetir.org/papers/JETIR2509261.pdf

"POLYSYNDACTYLY OF UNILATERAL THUMB OF THE LEFT HAND- A CADAVERIC CASE REPORT.", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.12, Issue 9, page no. ppc530-c535, September-2025, Available at : http://www.jetir.org/papers/JETIR2509261.pdf