Question

Polydactyly in man is due to

• A. Autosomal recessive allele
• B. Autosomal dominant allele
• C. Sex linked recessive allele
• D. Sex linked dominant allele

Answer 1

Answer: (B)

Autosomal dominant allele

Polydactyly is characterized by more than five fingers/digits in hand/foot. It can present alone or as part of many syndrome due to genetic disorder. It can occur by itself, or more commonly, as one feature of a syndrome of congenital anomalies. When it occurs by itself, it is associated with autosomal dominant mutations in single genes, i.e. it is not a multifactorial trait. But mutation in a variety of genes can give rise to polydactyly.
So, the correct answer is 'Autosomal dominant allele'