Not yet recruitingOBSERVATIONAL

Quantitative Assessment of the Etiologies of Megalencephaly Associated With a Detectable Tumor Risk

This study aims to understand why some children have a condition called megalencephaly, where their head and brain are larger than usual. We're particularly interested in identifying genetic causes that might increase a child's risk of developing certain cancers later in life. By finding these genetic links early, we hope doctors can recommend special check-ups to monitor for cancer and potentially improve health outcomes. The study will look at how often these cancer-related genes are found in children with megalencephaly and whether measuring head circumference could be a simple way to spot those who need further genetic tests. Ultimately, this research could help create better guidelines for looking after children with megalencephaly.

At a glance

Status

Not yet recruiting

Sponsor

Assistance Publique - Hôpitaux de Paris

Enrolment target

200

Start

01 Sep 2025

Estimated completion

01 Sep 2027

Megalocephaly

What is this study about?

Imagine a child whose head size is significantly larger than what's typical. Doctors often discover this during routine check-ups. Sometimes, a brain scan shows that the brain itself is larger than average, a condition called megalencephaly. When this happens, doctors often suggest genetic tests to find the exact cause, as part of a national plan for understanding brain conditions.

We already know of many genetic reasons why a child might have megalencephaly. Importantly, some of these genetic conditions also come with a higher chance of developing certain types of cancer. For these conditions, doctors usually recommend regular screening to catch any potential problems early. However, we don't fully understand how often these cancer-related genes are involved in all cases of megalencephaly, especially since everyone with megalencephaly doesn't get the same genetic tests.

This study is trying to fill that gap. We want to find out how many children with megalencephaly have these particular genes that increase cancer risk. The goal is to see if a simple measurement – head circumference – could be used by doctors to decide which children should have these important genetic tests sooner. By getting an early diagnosis, we hope to improve how these children are cared for and potentially prevent or treat cancer more effectively.

Key takeaways

The study looks at genetic causes of large heads/brains in children.
It aims to find genes linked to a higher cancer risk.
This could lead to earlier screening and better care for children.
Participation involves no extra tests or appointments.
Results may improve future guidelines for children with megalencephaly.

Who may be eligible?

To join this study, children need to have a head circumference that's much larger than average (what doctors call 'severe macrocephaly'). This must be confirmed by a brain scan showing they have megalencephaly (a larger-than-normal brain).

They also need to be in the process of having genetic testing (specifically, whole genome sequencing) to find out the cause of their megalencephaly. Their parents or guardians must agree for them to take part, and they need to be covered by a social security scheme.

Children cannot join if they already know the exact genetic cause of their megalencephaly, or if they've already had the specific genetic tests we're looking at for their megalencephaly in the past. This study focuses on children who are currently looking for an explanation for their condition.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Does your child have a very large head (diagnosed as severe macrocephaly)?
Has a brain scan confirmed that your child has megalencephaly (a larger-than-normal brain)?
Are doctors currently planning whole genome sequencing (a type of genetic test) for your child's megalencephaly?
Do you currently not know the exact genetic reason for your child's megalencephaly?
Has your child not had specific genetic tests for their megalencephaly in the past?

Answer every question to see your result.

What does participation involve?

The study does not involve new visits or assessments. It uses information from genetic tests that your child is already having as part of their routine care for megalencephaly. There are no new medications, and no additional follow-up appointments beyond what your child's doctors already plan. The study simply looks at the results of standard genetic testing to understand overall trends.

Potential risks and benefits

The main benefit of this study is for future patients. By participating, you’re helping researchers understand the links between megalencephaly and cancer risk, which could lead to better guidelines and earlier cancer screening for other children in the future. For your child, there are no direct medical risks as the study only uses information from tests they are already undergoing. There are no direct medical benefits for your child from being in this specific study, but the findings may indirectly help them and others by improving medical understanding. You are free to withdraw your child's data from the study at any time without affecting their medical care.

Locations (1)

service Génétique clinique Pitié-Salpêtrière / Trousseau
Verified postcode
Paris, France

Common questions

What is megalencephaly?

Megalencephaly means having a brain that is larger than average for a child's age.

Will my child get special treatment or medicine if we join?

No, this study doesn't involve any new treatments or medicines. It only uses information from tests your child is already having.

How long will my child be in the study?

There's no extra time commitment. The study simply uses existing information from your child's medical records and tests.

What is genetic testing?

Genetic testing looks at your child's genes to find out if there are any changes that might explain their condition.

Can we change our mind about being in the study?

Yes, you can withdraw your child's information from the study at any time, and it won't affect their medical care.

How to find out more

Solveig HEIDE, medical doctor

solveig.heide@aphp.fr 01 42 16 14 69 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.