{"id":808,"date":"2026-08-11T23:42:13","date_gmt":"2026-08-11T21:42:13","guid":{"rendered":"https:\/\/kleefstrasyndrome.com\/?page_id=808"},"modified":"2026-08-20T23:19:06","modified_gmt":"2026-08-20T21:19:06","slug":"faq","status":"publish","type":"page","link":"https:\/\/kleefstrasyndrome.com\/en\/qna\/","title":{"rendered":"Frequently Asked Questions"},"content":{"rendered":"
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Diagnosing a rare genetic condition like Kleefstra syndrome can raise many questions. It is not just about the person receiving the diagnosis, as the entire family tries to figure out what it means, what to expect, and what the next steps are. What exactly does the genetic result mean? What needs to be checked now? Will the child speak? Is an EEG needed? Is there a treatment? What does the diagnosis mean for a future pregnancy?; <\/p>\n\n\n\n

Especially in the beginning, the information may seem overwhelming and often contradictory. Every family needs its own time to process the diagnosis, organize its priorities, and find the answers it needs. From 2026, for the first time, there are international, evidence-based clinical guidelines specific to Kleefstra syndrome type 1 (KLEFS1)<\/strong>. The following answers are based primarily on these guidelines and are intended to explain in simple terms the most important points for a family at the beginning of this journey.<\/p>\n\n\n\n

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The information that follows is for informational purposes and does not replace personalized advice from a clinical geneticist, pediatrician, or other healthcare professional.<\/p>\n<\/blockquote>\n<\/div>\n<\/div>\n\n\n\n

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1. What exactly is Kleefstra syndrome?;<\/h2>\n\n\n\n

The Kleefstra syndrome type 1 (KLEFS1)<\/strong> it is a rare genetic neurodevelopmental condition caused by reduced gene function EHMT1<\/em>.<\/p>\n\n\n\n

The EHMT1<\/em> It is located on chromosome 9, in the region 9q34.3. In some individuals, there is a pathogenic variant within the gene itself, while in others there is a deletion of a chromosomal region that includes part or all of the EHMT1<\/em>. About half of the diagnosed cases belong to each of these two major categories, while rarer genetic mechanisms also exist.<\/p>\n\n\n\n

The syndrome can affect development, communication, learning, muscle tone, behavior, and different body systems. However, the presentation differs significantly from person to person<\/strong>.<\/p>\n\n\n\n

The diagnosis alone cannot accurately predict what a particular child will or will not be able to do in the future.<\/p>\n\n\n\n

2. What is EHMT1?;<\/h2>\n\n\n\n

The EHMT1<\/em> it is a gene that contains the instructions for producing a protein involved in regulation of the activity of many other genes<\/strong>.<\/p>\n\n\n\n

In KLEFS1, one of the two copies of EHMT1<\/em> is not functioning normally or is missing. The remaining functional copy is not sufficient to ensure the normal amount and function of the protein. This condition is called simple insufficiencyhaploinsufficiency<\/em>)<\/strong>.<\/p>\n\n\n\n

This is the basic molecular mechanism of the syndrome, which is why several modern research efforts are trying to increase or restore EHMT1 function.<\/p>\n\n\n\n

3. Did we do something wrong? Was it caused by something we did during pregnancy?;<\/h2>\n\n\n\n

No.<\/strong><\/p>\n\n\n\n

In most cases, the pathogenic variant that causes KLEFS1 is again<\/strong>, meaning it appeared for the first time in the child and was not inherited from either parent. Guidelines confirm that most pathogenic variants of EHMT1<\/em> arise in this way.<\/p>\n\n\n\n

It is not the result of any food, activity, medication the mother didn't know she shouldn't take, stress, lifestyle, or any parental mistake.<\/p>\n\n\n\n

Genetic variation is a biological event that occurs during the formation of germ cells or very early after conception.<\/p>\n\n\n\n

4. Is Kleefstra syndrome inherited?;<\/h2>\n\n\n\n

KLEFS1 is characterized as autosomal dominant genetic condition<\/strong>. However, in most families the mutation is de novo and neither parent has the same pathogenic mutation on routine genetic testing.<\/p>\n\n\n\n

However, there are exceptions.<\/p>\n\n\n\n

They have been described:<\/p>\n\n\n\n