Central precocious puberty (CPP) is a condition that causes early onset of sexual development in young girls and boys. Precocious girls begin to develop sexually before the age of 8, while boys develop before 9. Puberty is characterized by an increase in pubic and underarm hair, growth spurts, acne, and –for girls—their period begins and their breasts develop. Boys may also experience a drop in their voice and a growth in testes. In individuals with CPP, these symptoms appear at an early age; however, sexual development stops at an early age too. As a result, individuals with CPP might appear shorter than their peers as an adult.
CPP is caused by a mutation, or lack of function, in the MKRN3 gene. This gene is responsible for making a protein that blocks the release a hormone that stimulates the onset of puberty. Individuals with CPP do not produce this MKRN3 protein properly, so puberty begins earlier. Mutated, or changed, MKRN3 genes are inherited in an autosomal dominant manner. Autosomal dominant inheritance means that only one mutated, or changed, gene needs to be received from a parent for the individual to have CPP. Most individuals with CPP have a parent with the same condition.
Physicians can diagnose CPP during routine physical exams by examining early signs of puberty. A diagnosis of CPP can also be confirmed using MRI’s, thyroid tests, genetic testing, or blood samples. An MRI will show brain functioning that resembles CPP, while thyroid and blood tests measure levels of hormones or proteins that can be unusual as a result of CPP. Genetic testing can also determine if the individual has the gene associated with CPP.
Treatments exist to help prevent the onset of puberty, as well as other medications that prevent individuals from sexually developing. If you or a family member has been diagnosed with CPP, talk with your doctor about the best personal plan of action.
Description Last Updated: Aug 15, 2018