**Question:** In genetic profiling of seminal enzyme markers, Phosphoglucomutase (PGM) can be detected till

A. 10th week of gestation
B. 12th week of gestation
C. 16th week of gestation
D. 20th week of gestation

**Core Concept:** Phosphoglucomutase (PGM) is an enzyme that plays a crucial role in the regulation of glycolysis and gluconeogenesis in the body, particularly in the liver and kidney. In seminal fluid, PGM is produced by the seminiferous tubules of the testes. Genetic profiling of seminal enzyme markers is a method used to determine the paternity of a child, assess the genetic constitution of a male, and identify genetic disorders associated with the enzyme deficiencies.

**Why the Correct Answer is Right:** Phosphoglucomutase is expressed in the testes during fetal development, and its concentration decreases with gestational age. The correct answer, D, states that PGM can be detected till the 20th week of gestation. This is because PGM production is highest during fetal development, particularly during the 16th to 20th week of gestation, allowing for the detection of PGM in seminal fluid samples during this period.

**Why Each Wrong Option is Incorrect:**

A) The first option (10th week of gestation) is too early for PGM production to occur in significant amounts, as its expression in the testes is not established until fetal development.

B) The second option (12th week of gestation) is later than the peak of PGM expression in the testes, so its detection in seminal fluid would be less accurate due to lower enzyme concentration.

C) The third option (16th week of gestation) falls within the range of PGM detection but is still too early compared to the 20th week, which is the optimal time for genetic profiling of seminal enzyme markers.

**Clinical Pearl:** Genetic profiling of seminal enzyme markers, including phosphoglucomutase, can provide valuable information in legal cases involving disputed paternity or genetic disorders. It is essential to choose the most accurate gestational age when collecting seminal fluid samples to ensure reliable results in genetic profiling. The 20th week of gestation is considered the optimal time for collecting semen samples for genetic analysis due to the highest enzyme concentration present in the seminal fluid during this period.