A child with a small head, minor anomalies of the face including a thin upper lip, growth delay, and developmental disability can have all of the following,except: (A) A chromosomal syndrome, (B) A teratogenic syndrome, (C) A mendelian syndrome, (D) A polygenic syndrome
Answer is D. The features given can occur as a pa of a chromosomal / teratogenic / mendelian syndrome. Polygenic inheritance is the answer of exclusion. In a polygenic inheritance, multiple genes are involved in the phenotypic expression. Some examples of polygenic inheritance are hypeension and diabetes. Reference: GHAI Essential pediatrics, 8th edition