Learn: Understanding Lesch-Nyhan
This website was created by parents who understand firsthand what you are going through. Along the way, we’ve worked closely with medical experts to ensure the information we share is accurate and helpful.
We remember all too well the emotional impact of receiving a diagnosis like this—the fear, uncertainty, and overwhelming sense of grief that can make everything feel impossible.
With the support of families and our community who have walked this path, we’ve gathered resources to help answer your immediate questions and guide you forward.
The information here is comprehensive and may feel like a lot at first. That’s okay—take it one step at a time. Remember, Lesch-Nyhan Syndrome (LNS) often referred to as (LND) Lesch Nyhan Disease, exists on a spectrum, and not every child experiences every symptom. Most importantly, you are not alone. You will get through this, and we are here to support you in any way we can.
Understanding Lesch-Nyhan Syndrome
You are here (read below)
Signs and Symptoms
Studies and Research
Glossary of Terms
There are more than 2,000 gene mutations reported which affects one in 380,000 - 500,000 births worldwide
X linked Disorder
If the mother carries the HPRT mutation she has a 25% chance of having an affected male and a 25% chance of having a female who is a carrier. 50% having a child who does not have LN or is not a female carrier.
Basic Overview
Lesch-Nyhan Syndrome is a rare genetic condition that affects how the body processes certain natural substances. This can lead to high uric acid levels, movement challenges, and sometimes self-injurious behaviors. Each person with Lesch-Nyhan is unique, and with understanding, care, and support, families can help their loved ones thrive.
Every child with Lesch-Nyhan disease has their own story. Though the challenges can be real, their days are also filled with laughter, friendship, and love. They show us the strength of the human spirit and the beauty, they teach us about resilience, love, and the power of joy in every moment.
Classic Lesch Nyhan (LND) and Lesch Nyhan Variant (HND) is a dystonia movement disorder super imposed on hypotonia with normal strength.
Classic Lesch-Nyhan Disease
Self-injury is a hallmark feature of Classic Lesch-Nyhan disease and constitutes the most dramatic part of the behavioral phenotype. Although self-injury occurs in other intellectual disabilities, individuals with LND exhibit an unrelenting and diverse form of self-injury not otherwise observed. What also sets it apart is a dramatic increase in self injurious behaviors when punishment is used as a component of behavioral modification interventions. In addition to behaviors that impact every facet of their lives, Lesch Nyhan disease is a complex multisystem disability that requires ongoing care throughout the lifespan. (Gary Eddey MD, ScM(HYG), Kelly Henry MSW)
The characteristic evolution of motor involvement for Classic Lesch Nyhan is:
3-6 months: Hypotonia
6-24 months: Involuntary movements (predominantly dystonia)
24-48 months: Self injury and oppositional behavior
The Three Major Clinical Symptoms of Classic Lesch-Nyhan are:
Over production of uric acid
Neurologic disability
Self-injurious behaviors
Lesch-Nyhan Variant (HND)
Lesch Nyhan Variant (HND) is similar to classic LND, except the neurologic features are often less severe and self-injurious behavior does not occur.
The spectrum of the severity of neurologic features in HND is broad. The most severely affected individuals are neurologically indistinguishable from those with LND - without the behavioral component. And, the least severely affected individuals may have only minor clumsiness with fine motor activity or relatively minor cognitive deficits [Jinnah et al 2010]. Intermediate grades of severity may also occur. (Dr. Jinnah)
The Two Major Clinical Symptoms of Lesch Nyhan Variant (HND) are:
Over production of uric acid
Neurologic disability
Lesch-Nyhan Variant (HRH)
Lesch Nyhan Variant (HRH) does not have any behavioral or neurological manifestations it only has the increased serum uric acid.
The One Clinical Symptom of Lesch Nyhan Variant (HRH) are:
Over production of uric acid
HGPRT Enzyme Activity
HGprt, or Hypoxanthine-guanine phosphoribosyltransferase, is an enzyme crucial for the salvage pathway in purine metabolism. It plays a key role in converting hypoxanthine and guanine into purine nucleotides, contributing to the recycling of these essential cellular components. Mutations in the gene (HPRT 1) responsible for HGprt can result in disorders like Lesch-Nyhan Disease, characterized by neurological and behavioral abnormalities. This enzyme essentially helps maintain a balance in the purine building blocks our cells need.