In a family, the father has widely spaced eyes, increased facial hair and deafness. One of the three children has deafness with similar facial features. The mother is normal. Which one of the following is least likely pattern of inheritance in this case-

Ans. is 'a' i.e., Autosomal dominant (most likely) o It is typical presentation of waardeburg syndrome type - 1. --> Widely spaced eyes, Hearing loss, Increased facial hair o It is an autosomal dominant disorder. o In autosomal disorder, if one parent is affected and the other is normal, 25% of children (1 out of 4) will manifest disease.