Understanding Labrune Syndrome (LCC)

If you or a loved one has just been diagnosed with Leukoencephalopathy with calcifications and cysts (LCC), you are likely hearing this name for the first time. Often called Labrune syndrome after the doctor who first described it in 1996, it is a very rare condition that primarily affects the small blood vessels in the brain ^[1][2].

Because it is so rare, it is common for local doctors to have never seen a case before. Most of what medical science knows comes from a relatively small number of reported cases; as of recent literature reviews, roughly 90 to 100 cases have been documented worldwide ^[3][1]. Because many people may not be diagnosed correctly or their cases are not published, the exact number of people living with LCC is unknown.

Understanding the Name

The name of the condition is a literal description of what doctors see on brain scans like CT (computed tomography) or MRI (magnetic resonance imaging). To understand the diagnosis, it helps to break the name into its three parts:

• Leukoencephalopathy: This refers to disease in the “white matter” of the brain. White matter is the deep tissue that acts like a wiring system, carrying signals between different areas of the brain. In LCC, these areas appear abnormal or damaged on scans ^[4][1].
• Calcifications: These are hard, rock-like mineral deposits (calcium) that build up in specific parts of the brain, such as the basal ganglia (which helps control movement) and the thalamus (a relay station for information) ^[5][6].
• Cysts: These are fluid-filled sacs that form within the brain tissue. They can vary in size and may sometimes grow large enough to press on nearby structures ^[7][8].

Together, these three features are often called the “imaging triad.” While all three are usually present, they may not all appear at the same time. For instance, a person might have white matter changes and calcifications for years before a cyst is ever seen on a scan ^[9][10].

Causes and Diagnosis

LCC is a genetic condition caused by changes (mutations) in a gene called SNORD118 ^[11]. It is an autosomal recessive condition. This means a person must inherit a mutated copy of the gene from both parents to develop the syndrome ^[2]. When both biological parents carry a pathogenic variant, each pregnancy has a 25% chance of being affected, a 50% chance of being a carrier, and a 25% chance of being unaffected. A genetic counselor can discuss carrier testing, reproductive options, and risk assessment for siblings.

In the past, many cases were diagnosed based only on the “look” of the brain scans. Today, genetic testing can provide a definitive answer, but a confirmed molecular diagnosis requires finding appropriate biallelic pathogenic or likely pathogenic variants; a single variant or a variant of uncertain significance is not confirmatory. Furthermore, the SNORD118 gene is unique—it is a non-coding gene, which means it doesn’t provide instructions for making proteins the way most genes do. Because of this, standard genetic tests may miss it, and specialized testing is often required ^[12][13].

Who is Affected and What to Expect?

One of the most challenging aspects of LCC is how differently it affects each person. There is no “typical” case.

• Age of Onset: Symptoms can begin at any time. Based on the published literature, some children are diagnosed in infancy, while others do not show signs until up to 71 years of age ^[1].
• Progression: The course of the disease is highly variable. Some people experience symptoms that worsen slowly over many decades, while others may have more rapid changes ^[1][9].
• Symptoms: Because the condition affects the brain’s “wiring” and movement centers, common symptoms include difficulties with balance (ataxia), stiff muscles (spasticity), or involuntary movements (dystonia) ^[1][14]. Seizures and cognitive changes are also possible.

Crucially, the amount of “damage” seen on a scan does not always match how a person feels. Someone with extensive calcifications may have very few symptoms, while someone with a single large cyst may require immediate medical attention ^[13][15].

Looking Similar: LCC vs. Coats Plus

Doctors must distinguish LCC from another rare condition called Coats Plus syndrome (or CRMCC). While the brain scans for both look nearly identical, Coats Plus typically affects other parts of the body, such as the eyes (causing vision problems), the bones (leading to easy fractures), and the digestive system ^[16][17]. LCC is generally considered to be isolated to the brain, though clinical screening may still be appropriate when the genetic diagnosis is uncertain ^[16]. Distinguishing between the two is important because the long-term monitoring and treatment needs may differ based on systemic involvement ^[18].

The Path Forward

Because LCC is a chronic, lifelong condition, care usually involves a team of specialists. This often includes a neurologist (brain specialist) and a neuroradiologist (imaging specialist). Long-term monitoring with regular brain scans is standard practice to watch for changes in cysts or signs of pressure in the brain ^[1][19]. While there is currently no “cure” that reverses the genetic change, many of the symptoms—such as seizures or movement issues—can be managed with medications or, in some cases, surgical procedures to drain enlarging cysts ^[1][20].