This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
Which of the following is the least common cause of ambiguous genitalia in a female child- 
Select and explain. 
A. Fetal placental steroid sulfatase deficiency, B. Fetal placental aromatase deficiency, C. Congenital adrenal hyperplasia, D. WNT-4 gene mutation
A: Fetal placental steroid sulfatase deficiency
Answer: A: Fetal placental steroid sulfatase deficiency 
Explanation: Ans is 'a' i.e., Fetal placental steroid sulfatase deficiency o Placental steroid sufatase deficiency is an X-linked disorder (affects only males) that does not lead to ambiguous genitalia in a female child. o 'Placental steroid sullatase deficiency is a rare X-linked disorder and all affected fetuses are males' William's 22'd/8I o Congenital adrenal hyperplasia is the most common cause of ambiguous genitalia in female child. o Fetal placental aromatase deficiency and WNT-4 gene mutation cause ambiguous genitalia in female child.