The Beginnings of Super Humans

The Beginnings of Super Humans

The ideal body of an athlete is all muscle and no fat. It is the body many athletes choose to compromise their health in hopes of obtaining that perfect image of super strength and agility. On top of those abilities, imagine being able to eat whatever you want. That is exactly what a 3-year-old named Liam Hoekstra can do while holding the title of “World’s Strongest Toddler.” Liam was born with a rare genetic condition called myostatin-related muscle hypertrophy. Simply known as muscle enlargement.

Without harming the heart or any other medical problems, myostatin-related muscle hypertrophy promotes above-average growth of skeletal muscles. Affected individuals have up to twice the usual amount of muscle mass in their bodies. Symptoms depend on the amount of myostatin protein present. The condition is diagnosed by measuring skeletal muscle size by a MRI or DXA. The thickness of the fat in the body can be measured by caliper or ultrasound.

Mutations in the gene, MSTN, cause myostatin-related muscle hypertrophy. The MSTN gene provides instructions for making the protein called myostatin. This protein controls the growth of muscles and the movement of skeletal muscles both before and after birth. Myostatin normally restrains muscle growth, ensuring that muscles do not grow too big. Mutations that reduce the production of functional myostatin lead to the overgrowth of muscle tissue.

People inherit myostatin-related muscle hypertrophy through a pattern of inheritance called incomplete autonomic dominance. Individuals with a mutation in both copies of the MSTN gene in each cell (homozygotes) have increased mass and strength. Individuals with a mutation in one copy of the MSTN gene in each cell (heterzygotes) have the muscle mass to a lesser degree. That is the case with Liam Hoekstra who is believed to inherited the gene from his biological father.

At first glance, Liam Hoekstra’s appearance is that of a typical 3-year-old....