Congenital three generation wide familial non-syndromic polydactyly

Area of Science:

• Medical Genetics
• Orthopedics
• Human Anatomy

Background:

• Polydactyly, a congenital anomaly, often presents sporadically but can have familial occurrences with varied inheritance patterns.
• Approximately 30% of polydactyly cases have a family history, suggesting a potential single-gene involvement and the need for extensive family history evaluation.
• Investigating familial polydactyly across multiple generations is crucial for understanding its hereditary transmission and genetic basis.

Purpose of the Study:

• To report rare cases of congenital familial polydactyly extending across three generations.
• To document and analyze the specific types of polydactyly and associated anatomical variations within these families.
• To contribute to the literature on hereditary polydactyly, particularly focusing on autosomal dominant inheritance patterns and morphological anomalies.

Main Methods:

• Clinical analysis of three patients with foot polydactyly and their extended family members (first- and second-degree relatives) over two to three generations.
• Detailed examination of polydactyly types (central, postaxial) and morphological classifications (Y-shaped, T-shaped, duplicated ray metatarsals).
• Review of existing literature to compare findings with previously reported familial polydactyly cases across multiple generations.

Main Results:

• Identified three families with congenital polydactyly spanning three generations, suggesting autosomal dominant inheritance.
• Observed both central and postaxial polydactyly, with morphological variations including Y-shaped, T-shaped, and duplicated ray metatarsals.
• Documented a unique anatomical finding of a transverse accessory extensor tendon in patients with T- and Y-shaped metatarsals.

Conclusions:

• Congenital familial polydactyly can manifest across three generations with an autosomal dominant inheritance pattern.
• Significant morphological variations in metatarsals and associated tendons occur in familial polydactyly cases.
• These findings underscore the importance of detailed family history and anatomical assessment in managing and understanding polydactyly.