Precocious puberty happens when a child’s body starts to change into the body of an adult too early. Medical experts define this early-onset growth condition as puberty that occurs before age 8 in girls and before age 9 in boys. Infections, hormone dysfunction, brain injuries, genetics, and environment can all cause this pediatric disorder. However, precocious puberty also has a significant link with narcolepsy. Here’s what to know about the two conditions and their association.

What Is Precocious Puberty?

Normal puberty involves quick growth of muscles and bones, change in the size and shape of the body, and development of the body’s ability to reproduce. When a child undergoes precocious puberty, the following changes occur:

• Armpit and pubic hair appear.
• Boys grow facial hair and their voice deepens.
• Acne appears.
• Girls show breast development and start their period.
• Fast growth in height occurs, then it quickly stops at an early age.

These changes happen early during precocious puberty when a part of the brain called the hypothalamus begins making a hormone called gonadotropin-releasing hormone (GnRH). GnRH causes the body to make female and male hormones (estrogen and testosterone). Dysfunction in the ovaries, testicles, or hormone-making (endocrine) glands of the body may also lead to an extra release of estrogen or testosterone.

If left untreated, precocious puberty often leads to short stature. It can also cause serious issues with behavior and strong emotions. One study reports that children with precocious puberty show an increased likelihood for the following risky behaviors:

• Abusing substances
• Skipping school
• Having multiple sexual partners
• Acting out with poor behavior
• Withdrawing socially

What Is Narcolepsy?

Narcolepsy is a lifelong sleep disorder that most commonly develops during childhood and adolescence.

As a neurological sleep disorder, narcolepsy is marked by symptoms of:

• Experiencing excessive daytime sleepiness (hypersomnia)
• Feeling unable to move when falling asleep or awakening (sleep paralysis)
• Having intense dream-like visions when falling asleep (hypnagogic hallucinations) or while waking up (hypnopompic hallucinations)

Narcolepsy sometimes gives a person sudden muscle weakness (cataplexy).

There are two types of narcolepsy: narcolepsy type 1 and narcolepsy type 2. People with narcolepsy type 2 do not have cataplexy but experience severe daytime sleepiness. People with narcolepsy type 1 experience cataplexy and hypersomnia. The lack of the hormone hypocretin causes narcolepsy with cataplexy. Immune system attack on the hypothalamus likely leads to the low levels of hypocretin seen in people who have narcolepsy with cataplexy.

The Association Between Precocious Puberty and Narcolepsy

Having precocious puberty carries an association with narcolepsy. Both are rare conditions — narcolepsy has a prevalence of approximately 0.05 percent in the general population, and precocious puberty has a prevalence of 0.015 percent. If a child has narcolepsy with cataplexy, however, their risk of precocious puberty increases to 17 percent. This rate represents an almost 1,000-times higher rate of precocious puberty than in the average person.

Research shows that the younger a person is when they have their first symptoms of narcolepsy with cataplexy, the more likely it is that they have precocious puberty.

Compared to children with type 1 narcolepsy without precocious puberty, several factors are prevalent when a child has precocious puberty:

• Symptoms of narcolepsy appear an average of nearly three years earlier (at 6.64 years of age)
• Age of narcolepsy diagnosis is more than two years earlier on average (at 8.27 years of age)
• Misdiagnosis of narcolepsy jumps from 49.1 percent to 91.7 percent, on average

How Is Precocious Puberty Diagnosed and Treated?

A doctor may order the following medical tests to diagnose precocious puberty:

• Blood tests to check the levels of the child’s sex hormones
• Hand X-rays to verify the age of the bone
• Ultrasound images of the adrenal glands and the pelvis
• MRI or CT pictures of the brain to check for a brain tumor or other abnormalities

A doctor bases the treatment of central precocious puberty on the child’s age and speed of the disorder. If symptoms are worsening quickly, a specialist will likely recommend treatment in the form of GnRH stimulant therapy. This therapy causes an initial flare-up of the symptoms but then helps to decrease them as the brain cells become less sensitive to GnRH.

Prevention of Precocious Puberty

Besides type 1 narcolepsy, the following factors can raise a child’s risk of precocious puberty:

• Being female — Girls have a higher likelihood of the disorder.
• Being African American — Precocious puberty affects African American children more commonly than children of other races and ethnicities.
• Being obese — If a child has significant weight gain, their risk of precocious puberty increases.
• Undergoing radiation therapy of the brain or spinal cord — This treatment can raise the risk of precocious puberty.

There are some risk factors that a child cannot change, such as their race and sex. However, a parent or caretaker can do the following to reduce their child’s risk of precocious puberty:

• Keep the child away from outside sources of hormones, like adult medications or supplements that have testosterone or estrogen.
• Motivate the child to keep a healthy weight and offset any obesity with diet and exercise.

Talk With Others Who Understand

MyNarcolepsyTeam is the social network for people with narcolepsy. More than 8,000 members come together to ask questions, give advice, and share their stories with others who understand life with narcolepsy.

Are you or someone you care for living with narcolepsy? Do you have a child who is experiencing precocious puberty? Share your experience in the comments below, or start a conversation by posting on MyNarcolepsyTeam.