[Solved] In the context of hereditary disease, consider the following statements: 1. Passing on mitochondrial disease from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of egg. 2. A child inherits mitochondrial disease entirely from mother and not from father. Which of the statements given above is/are correct?

Q66. In the context of hereditary disease, consider the following statements:

1. Passing on mitochondrial disease from parent to child can be prevented by mitochondrial replacement therapy either before or after in vitro fertilization of egg.

2. A child inherits mitochondrial disease entirely from mother and not from father.

Which of the statements given above is/are correct?

A. 1 only

B. 2 only

C. Both 1 and 2

D. Neither 1 nor 2

Answer: C

_{Option c is correct.}

_{Statement 1 is correct. Mitochondrial replacement therapy (MRT) is a form of reproductive invitro fertilization (IVF) which works on the principle of replacing a women’s mitochondrial DNA (mt-DNA) with the donor’s healthy one. MRT include different techniques like spindles transfer (ST), pronuclear transfer (PNT) or polar body transfer (PBT).}

_{Pronuclear transfer technique is a significant approach of MRT administered after fertilization, in which two zygotes are raised in vitro.}

_{Maternal spindle transfer (MST) technique is executed before fertilization is a form of selective reproduction similar to prenatal diagnosis and pre-implantation genetic diagnosis (PGD)}

_{Statement 2 is correct. Mitochondria are the organelle which contain DNA in circular form, and in animals it is the only organelle in addition to nucleus which contain DNA and gene. The sperm contains very low number of mitochondria and mitochondrial gene. So, in the offspring the mitochondrial genes are inherited from the mother. Thus, a father with mitochondrial gene defect cannot transmit the disease to his offspring.}