Using CRISPR to engineer DNA in Human Sperm

You may be asking yourself what is CRISPR? Pronounced “crisper” and short for clustered regularly interspaced short palindromic repeats, CRISPR, debuted in 2012, is a family of DNA sequences found in the genetic material of unicellular organisms such as bacteria and archaea. When paired with the Cas9 enzyme, we can use CRISPR to genetically alter the DNA in sperm to prevent health conditions that are transferred to children through men -- Alzheimer's, HIV, forms of male infertility, genes that increase the risk of breast, ovarian, and prostate cancers to name a few. It sounds simple and picture-perfect, we’ll be looking at-- 

• How scientists are altering DNA with CRISPR
• Recent activity regarding CRISPR 
• How it could change human conception as we know it

How does it work?

CRISPR works similarly to our pre-established notion of cut and paste. 

It is a gene editing tool with two components -- Cas9 and a guide RNA. The Cas9 protein acts as a tool that can cut sections of a DNA strand. The guide RNA identifies the strands that will be edited. Together the team of Cas9 and RNA are inserted into the targeted cell, they locate the mutated sequence and cut the strand. After the DNA is cut, scientists can edit the existing genetic material by modifying, removing, or inserting a new sequence. 

Has the CRISPR tool been utilized in fertility treatments?

The short answer -- Yes. 

In November 2018, a Chinese scientist by the name of He Jiankui announced the birth of the first CRISPR engineered babies -- twin girls named Lulu and Nana. The goal was to help couples living with HIV produce babies that lack an HIV susceptibility gene -- essentially giving them immunity. 

Another announcement was made that a second woman was carrying a genetically engineered baby. The ethics of Jiankui’s motives were questioned by the Nanshan District People's Court of Shenzhen City -- he was found to have acted in the goal of gaining personal fame and also disrupting medical order. He received a three year prison sentence and a $480,000 fine. 

Where do we go from here? 

It sounds perfect -- we edit out some of the world’s most prevalent health conditions from male sperm before babies are even conceived. Too good to be true? This technology brings back questions surrounding the morality and ethics of gene editing. 

CRISPR allows us to move closer to the concept of “designer babies” -- a baby whose genes have been altered or specifically selected to exclude certain diseases. 

However, instead of altering an embryo we can take this a step further and fix sperm to include our desired genetic makeup. 

Aside from the case in China, human trials in the US have not been used to engineer a baby. Instead, cells were removed from patients with pre-existing health conditions, such as cancer and blood disorders. The cells were then edited and reinjected with the goal of fighting the condition. 

CRISPR technology has also been used to alter the genetic makeup of some foods. The technology brings with it a range of possibilities for the future of not only child conception, but also health treatments and food supply transformation.