Forever young: the strange case of a child who does not age

Brooke Greenberg (l) with her sister, Carly. (Greenberg/ABC)

Everyone wishes they could remain young or at least look that way once in a while. For some children, however, old age comes too quickly or not at all. And for at least one child, her conception predates her birthday by more than a decade, instead of the usual 40 weeks.

In the case of Brooke Greenberg of suburban Baltimore her young appearance is a medical mystery. Young Brooke looks and has the mental capacity of a toddler, but chronologically she is 16 years old. According to her physician Lawrence Pakula, M.D., an associate professor of pediatrics at Johns Hopkins University, the cause of her condition is unknown and her case may be “unique.” Other than the fact that she was born a month premature and weighed just 4 pounds at birth, news stories about Brooke say her physicians have never diagnosed her with any “known genetic syndrome or chromosomal abnormality.”  Brooke’s doctors describe her aging process as “disconnected” with her bones showing a chronological age of about 10 years while her vocalizations are that of an infant. But her mother says she loves to shop like a teen, and her sister claims she rebels like one too.

Brooke may be one-of- a-kind, but her condition could hold some clues as to why and how fast we age. There are dozens of conditions that fool with the body’s natural aging process. The National Institute on Aging list many diseases that alter the natural course of aging, most of which seem to arise from genetic origins such as mutations, deletion or unfortunate pairings of gene code.

A condition called Werner's Syndrome (WS), for example, is a homozygous recessive disease. That means a person with this condition carries the non-dominant trait from each parent in his or her DNA. Werner’s Syndrome typically sets in at puberty with wrinkles and gray hair. Patients also develop cataracts, diabetes, and osteoporosis.

Another condition called Cockayne syndrome (CS) also causes premature aging. With CS, if a person is exposed to ultraviolet light, their DNA cannot repair itself. Aging advances with each exposure to sunlight.

Many people have heard of a disease that causes rapid aging called Progeria or Hutchinson-Gilford Progeria Syndrome. This rare condition results from a mutation of the LMNA gene (or lamin-a), which is responsible for retaining the structural integrity of the cell’s nucleus. When the nucleus becomes unstable, cells prematurely age.

And what of cellular aging? There’s the case of Shani Moran-Simmonds of Birmingham, Great Britain, who was born just two-and-a-half years ago, but  was actually conceived more than 12 years prior. For a variety of reasons, her fertilized embryo remained frozen until her parents decided to have the embryo, along with several others, thawed and implanted in Shani’s mother. Shani's embryo survived to full term. A story from the UK’s Daily Mail says that it is thought that Shani is “one of the world's oldest frozen babies - or 'Frosties' as they are known.”

Did Shani’s DNA “age” during that time, even though her embryo remained frozen and undifferentiated for more than 10 years? Only time will reveal if the delay from conception to birth will have any ill effects on the child.

Some scientists who study aging have been looking at the telomeres of our DNA for clues. The telomeres are long repeating strands of nucleotides that cap the ends of our DNA to protect it from degradation. Each time the DNA replicates, the telomeres become shorter and shorter.

Some studies show that life’s stressors increase the rate at which our telomeres shorten, skimming years off of our lives. Anything that damages or otherwise alters the state of our telomeres, these scientists say, can cause our natural aging process to go awry.

Other scientists dispute the telomere theory. They suggest that the key to aging (and maybe the Fountain of Youth) lies elsewhere. A handful of other theories exist, including the neuroendocrine system theory, one that says aging is caused by a build-up of toxins, or that we age every time glucose binds to our proteins--the glycosylation theory.

But none of those theories or ideas can explain what is happening to Brooke Greenberg, who seems, at least by outward appearances, to remain forever young. ABC’s “20/20” will air a story on Brooke this Friday, June 26 at 10 p.m. ET. A documentary on Brooke and her family will air on TLC Sunday, August 9 at 9 p.m. ET.

How old do you feel?

Credit by Jirí Mašek