Girls and Women
affected by LND
Affected Female Individuals
What Is Lesch–Nyhan Disease (LND)?
Lesch–Nyhan disease (LND) is a rare genetic condition caused by a change in a gene called HPRT1.
This gene is located on the X chromosome and is responsible for helping the body recycle certain building blocks of DNA. When this gene does not work correctly, it leads to the features seen in LND.
How X Chromosomes Work
Girls typically have two X chromosomes—one from their mother and one from their father.
Boys typically have one X and one Y chromosome.
Because LND is linked to the X chromosome, the number of X chromosomes a person has plays an important role in how the condition affects them.
Why LND Usually Affects Boys
Boys have only one X chromosome. If that X chromosome carries the HPRT1 gene mutation, there is not a second (good) X chromosome to compensate, so boys are usually affected by LND. In boys, LND is rare, because getting a gene mutation is uncommon.
Why Most Girls Are Not Affected
Girls have two X chromosomes. In most girls who carry only one HPRT1 mutation, the condition does not cause symptoms because of a process called random X-inactivation (also known as lyonization). During early development, one X chromosome in each cell is randomly turned off.
If a girl has one affected X chromosome and one healthy X chromosome, many of her cells will still use the healthy copy. When enough cells express HPRT1 from the good X chromosome, there is sufficient activity to prevent any symptoms. In other words, the good second X chromosome can compensate for the mutation on the other X chromosome.
How Girls Can Be Affected
Although rare, girls can also be affected under very, very rare circumstances:
Spontaneous (de novo) gene mutations
The HPRT1 gene change can occur by chance during egg or early embryonic development, even if neither parent is a carrier.Non-random X-inactivation
leading to preferential expression of the X chromosome with the mutant HPRT1 gene. Sometimes the body turns off the healthy X chromosome more often than expected, leaving fewer cells able to make the needed enzyme.Problems with the second X chromosome (Structural or functional abnormalities)
If the second X chromosome is missing, altered, or not fully functional, it may not compensate for the affected X chromosome.Both copies of the HPRT1 gene are affected on each X chromosome.
Symptoms in girls can range from very mild to more significant and may look different from those seen in boys.
Life Stories of Affected Girls and Women with Lesch-Nyhan
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Coming soon
Why Symptoms Can Vary
LND affects individuals differently. The type of gene change, how much enzyme activity remains, and how X-inactivation occurs all contribute to variability in symptoms, especially in females.
Research continues to expand our understanding of how these mechanisms influence symptom severity and variability in females with LND.
Ongoing Research and Education
Love Never Sinks – Lesch–Nyhan is committed to providing clear, accurate, and family-centered information as research evolves. We are actively working on resources that explain LND genetics in ways that support both families and clinicians.
Frequently Asked Questions
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Yes. LND is inherited in an X-linked pattern, but it can also occur due to a spontaneous (new) gene mutation.
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Boys have only one X chromosome. If it carries the LND gene mutation, there is no backup copy to compensate.
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Yes, although it is very, very rare. Girls may have symptoms due to skewed X-inactivation, spontaneous mutations, problems with the second X chromosome or both copies of the HPRT1 gene are affected on each X chromosome.
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The gene mutation can occur spontaneously during early development, even when neither parent is a carrier.
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No. Many girls are carriers without symptoms.
When/If symptoms do occur, they can range from mild to more significant and vary from person to person.
It is very, very rare for a female to be affected with classic Lesch-Nyhan. But it can happen.
Remember the Girls is an excellent reference for Women and Girls who are carriers of a X Chromosome related disease and want to be on conversations about family planning and discussions about carrier status and advocacy.
Checking the Family - more information about finding out carrier Status Lesch-Nyhan.Org
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Yes. Researchers continue to study why symptoms differ between individuals and how genetic mechanisms affect disease expression, especially in females.
The NIH currently has an ongoing study of Female Carriers of Lesch-Nyhan open to US and Canadian residents.
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Chromosome abnormalities can be numerical or structural. A numerical abnormality mean an individual is either missing one of the chromosomes from a pair or has more than two chromosomes instead of a pair. A structural abnormality means the chromosome's structure has been altered in one of several ways. Fact Sheet
If your child has recently been diagnosed with Lesch-Nyhan, it's important to understand the signs and symptoms associated with the condition. This information can help you better understand the individual’s needs and advocate for appropriate care.
Children and Adults with Lesch-Nyhan may experience a variety of symptoms, including self-injurious behavior, neurological problems, motor difficulties, kidney stones, and gout. However, it's important to remember that each child's experience with the condition will be unique.
If you have any questions or concerns about your child's or adult’s symptoms, please talk to your doctor. They can help you understand the individual’s specific needs and provide appropriate care