Kleefstra syndrome

Common Name(s)

Kleefstra syndrome, Chromosome 9q deletion syndrome, 9q34.3 deletion syndrome, 9q34.3 microdeletion syndrome, 9q- syndrome

Kleefstra syndrome, also known as a 9q34.3 deletion, falls into a category of chromosome disorders in which a small segment of chromosome 9 is missing. This means instead of two copies of the genes in this segment, each cell of the body now only has one copy. The missing copy of genetic information may cause multiple birth defects and developmental issues.

Symptoms of this condition may include developmental delays, requiring support with learning, low muscle tone (hypotonia), heart conditions, seizures, high pain tolerance, and an increased risk for developing respiratory infections. Most affected children are not able to use verbal speech, so they generally use nonverbal forms of communication like hand gestures. Individuals with this condition generally have a similar appearance of a broad head, low eyebrows that sometimes meet in the middle, wide spaced eyes, a short upturned nose, large tongue, and a narrow mouth with a pushed out bottom lip.

Mutations (changes) in the gene EHMT1 are what cause Kleefstra syndrome. The condition can be inherited from a parent in an autosomal dominant manner (a mutation in one copy of the gene causes the condition). However, the condition more commonly arises by random chance (de novo), and the parents’ chromosomes are normal. The condition is officially diagnosed with a genetic test that allows a specialist to see that a specific portion of the chromosome is missing.

Although there is currently no cure for Kleefstra syndrome, there are various resources to help manage the condition and treat birth defects. Doctors seek help from various therapists and community services to provide support and care for families. Support groups are also a great resource for support and information. Talk with a genetic counselor or specialist if you or someone in your family has been diagnosed with Kleefstra syndrome.

Source: Advocacy organizations associated with the condition.

 

Advocacy and Support Organizations

 

Condition Specific Organizations

Following organizations serve the condition "Kleefstra syndrome" for support, advocacy or research.

Chromosome 9 Disorder Advocates

Changing the world one chromosome and one hope at a time. We are your voice and your direction if ever you feel speechless or lost.

Last Updated: 8 Jan 2014

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Simons VIP Connect

The Simons Variation in Individuals Project (Simons VIP) is an online community and research initiative. We provide a platform to partner families and researchers to better understand over 40 genetic changes (genomic variants) associated with features related to autism and developmental delay.

Last Updated: 22 Apr 2015

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The Focus Foundation

The Focus Foundation is dedicated to helping children and families affected by X & Y Variations, Dyslexia, and/or Developmental Dyspraxia. The Focus Foundation believes that through increased awareness, early identification and syndrome-specific treatment, children with these conditions can reach their full potential.

Last Updated: 31 Mar 2015

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General Support Organizations

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How do you compare to others with this condition?

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Advocacy and Support Organizations

 

Condition Specific Organizations

Following organizations serve the condition "Kleefstra syndrome" for support, advocacy or research.

Chromosome 9 Disorder Advocates

Changing the world one chromosome and one hope at a time. We are your voice and your direction if ever you feel speechless or lost.

http://chromosome9.org

Last Updated: 8 Jan 2014

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Simons VIP Connect

The Simons Variation in Individuals Project (Simons VIP) is an online community and research initiative. We provide a platform to partner families and researchers to better understand over 40 genetic changes (genomic variants) associated with features related to autism and developmental delay.

http://www.simonsvipconnect.org

Last Updated: 22 Apr 2015

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The Focus Foundation

The Focus Foundation is dedicated to helping children and families affected by X & Y Variations, Dyslexia, and/or Developmental Dyspraxia. The Focus Foundation believes that through increased awareness, early identification and syndrome-specific treatment, children with these conditions can reach their full potential.

http://www.thefocusfoundation.org/

Last Updated: 31 Mar 2015

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General Support Organizations

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General Resources

46,XY,del(9)(q31.2q33.1)

Single case chromosome disorder in 9

Updated 27 Nov 2013

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Scientific Literature

Articles from the PubMed Database

Research articles describe the outcome of a single study. They are the published results of original research.
The terms "Kleefstra syndrome" returned 2 free, full-text research articles on human participants. First 3 results:

A mosaic maternal splice donor mutation in the EHMT1 gene leads to aberrant transcripts and to Kleefstra syndrome in the offspring.
 

Author(s): Andreas Rump, Laura Hildebrand, Andreas Tzschach, Reinhard Ullmann, Evelin Schrock, Diana Mitter

Journal: Eur. J. Hum. Genet.. 2013 Aug;21(8):887-90.

 

The euchromatic histone-lysine N-methyltransferase 1 (EHMT1) gene was examined in a 3-year-old boy with characteristic clinical features of Kleefstra syndrome. Sequencing of all 27 EHMT1 exons revealed a novel mutation, NM_024757.4:c.2712+1G>A, which affects the splice donor of intron ...

Last Updated: 18 Jul 2013

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Hippocampal dysfunction in the Euchromatin histone methyltransferase 1 heterozygous knockout mouse model for Kleefstra syndrome.
 

Author(s): Monique C M Balemans, Nael Nadif Kasri, Maksym V Kopanitsa, Nurudeen O Afinowi, Ger Ramakers, Theo A Peters, Andy J Beynon, Sanne M Janssen, Rik C J van Summeren, Jorine M Eeftens, Nathalie Eikelenboom, Marco Benevento, Makoto Tachibana, Yoichi Shinkai, Tjitske Kleefstra, Hans van Bokhoven, Catharina E E M Van der Zee

Journal: Hum. Mol. Genet.. 2013 Mar;22(5):852-66.

 

Euchromatin histone methyltransferase 1 (EHMT1) is a highly conserved protein that catalyzes mono- and dimethylation of histone H3 lysine 9, thereby epigenetically regulating transcription. Kleefstra syndrome (KS), is caused by haploinsufficiency of the EHMT1 gene, and is an example ...

Last Updated: 4 Feb 2013

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Reviews from the PubMed Database

Review articles summarize what is currently known about a disease. They discuss research previously published by others.
The terms "Kleefstra syndrome" returned 0 free, full-text review articles on human participants.

 
 
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Clinical Trial Information This information is provided by ClinicalTrials.gov

There are currently no open clinical trials for this condition.