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
Correct answer : D. A polygenic syndrome
The features given can occur as a part 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 hypertension and diabetes.