Anecdotal experience suggests that the final heights of the treated kids should fall with 2 to 3 inches of their genetically predicted heights. Some can gain as many as 4 to 5 inches of height.
"Even when they have a condition that predisposes them to shortness, it's better to have tall parents," said Dr. Mitchell Geffner, a pediatric endocrinologist at Children's Hospital Los Angeles and professor of pediatrics at Keck School of Medicine at University of Southern California.
Although growth hormone is used for short stature children who are otherwise normal, "in this case, it's not cosmetic," he said.
Children with RSS can be treated as early as 2 and continue treatment for 10 years, Geffner. "Generally, it's true; starting early, you have more time to use it. You let it linger and they'll fall further away and have more ground to recover."
Growth hormone has been used for 50 years and it has been a synthetic form since 1985. "It has an amazingly safe record," he said.
Ian receives one injection a day at home. The side effects are rare and usually reversible.
But the biggest challenge is social.
"People are extremely judgmental," Earley said. "We as society talk about being big: 'Look how big you are,' 'What a big boy,' but Ian is not big and he never will be big.
"They have no clue how difficult it is. When you can't get a child to eat, it's very scary," she said. "You are responsible for that child, to love and nurture. ... It becomes emotionally exhausting."
And because the syndrome is so rare, children often go undiagnosed.
"It's unknown, even in the medical community," said Mary Andrews, founder and CEO of the Magic Foundation, which supports families with growth disorders. "Unfortunately, it's tough to diagnose."
But the good news is that many of these children can live normal lives.
The Magic Foundation supports families such as the Earleys with new research and connects them to other families for support.
"We make sure they know every resource available for the children," Andrews said. "When a family calls to say they have a child with Russell-Silver syndrome, we put them on the phone and refer them to a division consultant -- someone who has a child with Russell-Silver -- so they can talk one-on-one."