New study records the frequency of Kleefstra syndrome features in 172 individuals

In 2024, Tanja Zdolšek Draksler and her colleagues published in European Journal of Medical Genetics a study that utilized data from 172 individuals with Kleefstra syndrome (KLEFS1), recorded on the international platform GenIDA. The information was provided by parents and caregivers and was used to capture the presence, frequency, and estimated severity of different characteristics of the syndrome.

The value of the study lies mainly in the size of the international team and the fact that it systematically gathers the experience of families regarding a rare syndrome for which available data remain limited. The authors themselves emphasize the usefulness of caregiver-reported registries in rare diseases, as well as the need for even more specific and improved data collection methods.

Which features were mentioned most frequently?;

According to caregiver reports, among the most frequently recorded problem groups were behavioral disorders, vision problems, neonatal period problems, walking difficulties, and intellectual disability.

In the data presented by the study, the following were recorded, among other things:

• behavioral disorders: 67,1%
• vision problems: 66,9%
• problems of the neonatal period: 66,5%
• walking difficulties: 65,6%
• intellectual disability: 64,7%
• musculoskeletal problems: 57,3%
• Gastrointestinal issues: 57,1%
• eating disorders: 52,1%
• sleep disorders: approximately 50%
• cardiac abnormalities: 39,9%

For example, regarding vision problems, 166 caregivers responded, and 111 reported such a problem, representing 66.9%.

Seizures were reported in about a quarter of the participants, and autism spectrum diagnoses were also recorded.

What does this study add?;

The study does not attempt to define a single «typical» profile for every individual with Kleefstra. Instead, it shows the phenotypic polymorphism and how many systems of the organism may be involved.

At the same time, it offers a different source of information from classical clinical series: the daily observation of people living alongside individuals with the syndrome. This is particularly useful in rare diseases, where large clinical cohorts are difficult to assemble. The authors believe that such collections can provide important data, while simultaneously pointing out that recording systems need further improvement and greater specialization.

Why do family reports matter?;

Families often observe traits that span a long period of time and different aspects of daily life — sleep, feeding, behavior, mobility, communication, and others.

This does not mean that caregiver reports replace clinical evaluation. However, they can work complementarily and help in better describing the natural history of a rare syndrome. The study itself focuses precisely on the usefulness of this form of data collection.

Note: The article is an informative summary of this specific scientific publication and does not constitute medical advice. The percentages are derived from reports of caregivers who participated in this specific study and should not be considered as absolute frequencies for all individuals with Kleefstra syndrome.