RecruitingNAINTERVENTIONAL

Transcriptomic Analysis of Fibroblasts and Blood in Patients With Rare Diseases

Doctors often struggle to find the exact cause for children and adults who have learning difficulties or very weak muscles from birth, even after many genetic tests. This study aims to help fix this problem. We believe that some people might have differences in their RNA (a molecule that helps carry out instructions from DNA) that current DNA tests miss. By studying RNA from blood and skin samples, researchers hope to find new ways to diagnose these rare genetic conditions. This could lead to a diagnosis for more patients and help doctors decide if a blood test alone is enough for future speedy diagnoses.

At a glance

Status

Recruiting

Phase

Sponsor

Assistance Publique Hopitaux De Marseille

Enrolment target

Start

09 Mar 2026

Estimated completion

30 Apr 2029

Rare Genetic Disease

What is this study about?

Imagine your body's instructions are like a recipe book. Your DNA is the main recipe book, and RNA is like a copy of a recipe that your body uses to make different things. For many people with rare genetic conditions that cause intellectual disability (learning difficulties) or neonatal hypotonia (floppy baby syndrome/very weak muscles from birth), doctors can't find the 'mistake' in the recipe book, even after checking the DNA very carefully.

This study is trying a new approach. Researchers think that the 'mistakes' might not always be obvious in the main recipe book (DNA), but rather in the copies (RNA) that the body makes. They want to see how often these 'mistakes' in RNA happen in people who haven't yet received a diagnosis for their condition. By looking at these RNA 'mistakes', they hope to find answers for more patients.

The study also aims to compare taking samples from blood and from a small piece of skin. This will help them understand which type of sample is best for finding these RNA 'mistakes'. Ultimately, the goal is to make it easier and faster for doctors to diagnose these rare conditions in the future, helping patients and their families understand their health better.

Key takeaways

The study aims to diagnose rare genetic conditions when standard tests aren't enough.
It focuses on looking at 'RNA mistakes' instead of just DNA.
Participation involves a blood sample and a small skin sample.
This research hopes to provide answers for undiagnosed patients.
Findings could help develop faster diagnostic methods in the future.
You can stop participating at any time.

Who may be eligible?

This study is looking for children or adults, aged 0 to 99, who have been seen at one of the participating hospitals for intellectual disability (learning difficulties) or neonatal hypotonia (very weak muscles from birth).

To join, a major requirement is that previous genetic tests, which looked at your DNA, like gene panel tests, exome sequencing, or genome sequencing, did not find a clear explanation for your condition. Also, if your specific symptoms suggested certain conditions like Prader-Willi, Angelman, Fragile X, or Myotonic Dystrophy type 1, tests for these specific conditions must have come back negative.

There are also some reasons why someone could not join. For example, if you are pregnant or breastfeeding, or if the person who needs to give consent doesn't understand French, you wouldn't be able to take part. Also, if a person is legally unable to make decisions for themselves (under guardianship or curatorship) or is deprived of their freedom (e.g., in prison), they cannot participate.

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.

Are you between 0 and 99 years old?
Do you have intellectual disability or weak muscles from birth?
Have you had extensive DNA genetic tests that didn't find an answer for your condition?
Are you able to provide informed consent (or can a parent/guardian do so)?
Are you not currently pregnant or breastfeeding?
Do you understand information provided in French, or is someone available to translate if needed?

Answer every question to see your result.

What does participation involve?

If you decide to take part in this study, you would need to provide two types of samples: a blood sample and a small skin sample (this is called a skin biopsy). The blood sample is usually taken from your arm, similar to a routine blood test. For the skin sample, a very small piece of skin, about the size of a pencil eraser, would be taken, usually from an area that isn't very noticeable.

There are no medications involved and there are no extra follow-up visits specifically for this study. The samples would be collected, and then the researchers would analyse them in a laboratory. The total duration of your direct participation in terms of giving samples would be brief, likely just one visit for sample collection.

Potential risks and benefits

Participating in this study might offer a potential benefit by helping researchers understand rare genetic conditions better, and it's possible that this research could eventually lead to a diagnosis for you or your child, which could provide answers and help guide future care. The risks involved are minimal, mainly discomfort from the blood draw and the small skin biopsy, and a small chance of bruising or infection at the sample sites. You are free to withdraw from the study at any time without giving a reason, and this will not affect your usual medical care.

Locations (1)

Assistance publique - hôpitaux de Marseille
Verified postcode
Marseille, France· Recruiting

Common questions

What is the main goal of this study?

The main goal is to find new ways to diagnose rare genetic conditions that cause learning difficulties or weak muscles, especially when previous tests haven't found an answer.

What does 'RNA mistakes' mean?

It means looking for differences in the 'working copies' of your genetic information (RNA) that might explain your condition, even if your main genetic code (DNA) appears normal.

What samples will be taken?

You will be asked to provide a blood sample and a very small skin sample (a skin biopsy).

Will I get a diagnosis from this study?

The purpose of this study is research, not direct diagnosis. However, the findings could potentially lead to a diagnosis for you or your child in the future. The researchers will let you know if they find anything important for your case.

Is there any cost to take part?

No, there are no costs for participating in this research study.

How to find out more

Svetlana GOROKHOVA, MD

svetlana.gorokhova@ap-hm.fr 33491388499 Official trial record

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