When we first heard the diagnosis, it felt like our world collapsed around us.

The histopathology report following the biopsy read as follows:

Pilocytic astrocytoma (WHO grade 1), with a BRAF V600E mutation

Turning to the medical literature, we found:

Pilocytic astrocytoma (PA) is a slowly growing, low-grade brain tumor (pediatric low-grade glioma – pLGG) that arises from astrocytes, the supportive cells of the nervous system. It occurs most commonly in children and young adults.

At first, it brought some relief and something to hold onto that, according to WHO classification, pilocytic astrocytoma is a grade I glioma, which in many cases is treatable.

However, looking back now, life has not confirmed that “treatability” for Bertold. Several factors make effective treatment harder in his case:

-> his very young age ( years),

-> the tumor’s midline location,

-> its extension into multiple brain regions,

-> and the specific genetic mutation (BRAF V600E).

In Bertold’s case, the disease is driven by a defect in the BRAF gene , which causes the tumor cells to divide without control.

The BRAF gene is involved in regulating the MAPK signaling pathway, which controls cell growth and division. As a result of the mutation, the protein remains constantly active (“switched on” ), leading to uncontrolled cell proliferation.

Despite all our efforts, Bertold’s cells keep dividing relentlessly, and the tumor repeatedly forces its way back.

It is important to know that in most cases these genetic changes are not inherited but arise spontaneously during a child’s development. The exact cause is currently unknown. Likewise, the behavior and exact nature of the tumor cannot be predicted with certainty. In rare cases, the tumor may even mutate and become malignant.

Symptoms depend on the tumor’s precise location (cerebellum, optic pathway, hypothalamus/brainstem) and can be wide-ranging:

-> headaches,

-> hydrocephalus,

-> balance and motor disorders,

-> vomiting,

-> visual disturbances or vision loss,

-> epileptic seizures,

-> hormonal/endocrine disorders,

-> growth delay, developmental regression,

-> behavioral changes or cranial nerve damage.

Unfortunately, several of these have occurred in Bertold.

at six months old, his head circumference far exceeded the average and “rose above” the percentile curve,

his vision progressively narrowed, and his nystagmus worsened,

delays appeared in his cognitive development,

and from late 2024, epileptic seizures also appeared, making daily life even more difficult.

Despite all this, Bertold is incredibly strong. Compared to his peers, his development is slower, but following his own path, he fights day by day to move forward.

After receiving the diagnosis, we reviewed the possible treatment options, which may include:

Surgery: The first-line therapy, but not possible in Bertold’s case due to the tumor’s location.

Chemotherapy: It can be used, but is often only partially effective because the problem lies not with cell division itself but with its regulation. In Bertold’s case, it brought mixed results.

Targeted therapies (first-generation inhibitors): There are drugs that specifically target the BRAF V600E mutation. In addition, other agents are available that inhibit the MAPK pathway by different mechanisms—the so-called MEK inhibitors.

Bertold’s first treatment was a combination of a BRAF and a MEK inhibitor. Although the inhibitors initially brought improvement, later the tumor began to grow again despite their use.

Radiotherapy: Not recommended in very young children due to serious long-term side effects. (In Bertold’s case, proton therapy is also not an option because of the tumor’s size and location.)

The new hope : Tovorafenib

In parallel with starting chemotherapy, our attention turned to a new targeted therapy that appears more effective than those used so far—namely, Tovorafenib. This new, so-called second-generation inhibitor could significantly improve Bertold’s outlook: it may stop the tumor’s growth or even shrink it, reduce symptoms, and provide a better quality of life.

Tovorafenib is a broad-spectrum pan-RAF kinase inhibitor that is effective against BRAF fusions and mutations (e.g., V600E).

This treatment could give Bertold the chance to live the kind of life every child deserves.