Kleefstra Syndrome

Overview

Kleefstra Syndrome is a rare genetic condition. A small piece of the long arm of one of the child's 9^th chromosomes is missing. As a result, a gene, called Eu-chromatin-Histone Methyl Transferase  or EHMT1, is missing from the chromosome. It is this missing gene that is thought to cause the majority of the symptoms these children exhibit (Rare Chromosome, 2). Researchers have discovered that EHMT1, causes other genes to be silenced (not active). In the case of Kleefstra Syndrome, one copy of the EHMT1 gene is lost, therefore less protein will be formed and the silencing of its target genes is not sufficient anymore. This is called 'loss of function' or 'haploinsufficiency' of EHMT1 (Kleefstra, T. 2009).  Basically, EHMT1 blocks unwanted gene activity. Without sufficient amounts of this protein, undesirable characteristics can develop. These range from serious heart defects, seizures and renal issues to minor characteristics such as a “uni-brow” or a slightly upturned nose. Both of which are physical characteristics common in Kleefstra Syndrome.

Until recently it was thought that the size of the child's deletion was directly related to the number and severity of symptoms the child would experience. It is now known that it is not the size of the deletion but the location of the break on the chromosomal arm that is important. Often more then just one gene is affected in a deletion, which will cause a variety of issues depending on which genes are affected. However, it is the deletion of EHMT1 specifically that results in a diagnosis of Kleefstra Syndrome (Kleefstra and Yatsenko, 2009).

Symptoms

Kleefstra Syndrome is characterized by cognitive delay, gross motor delay caused by childhood hypotonia, distinct facial features, immature sexual organs in males, and a lack of expressive speech. A “complex pattern” of secondary characteristics have also been observed. These can include heart defects, renal defects, severe respiratory infections, GERD, epilepsy/febrile seizures, autistic-like behaviours, and extreme aggression (males) or catatonic-like (females) features after the onset of puberty (Kleefstra, 2010).

Physical Characteristics Males and females are affected equally. Birth weight is usually within the normal or above normal range whereas in childhood weight increases leading to obesity. The facial appearance is characterized by a small head circumference, broad forehead, synophrys or “uni-brow”,  mildly up slanting eye lids, mid facial hypoplasia (the jaw and cheekbones do not develop as quickly as the rest of the face), thickened ear helices, short nose with an upturned tip, cupid bowed upper lip, and protruding tongue (Kleefstra, T. 2009). Many of these characteristics are what may lead a doctor to suggest genetic testing. They are common in a number of genetic defects (Belanger, 2010). Education of geneticists in these characteristics may one day lead to Kleefstra Syndrome being diagnosed at birth and not after years of testing for other syndromes.

Behaviour Children with Kleefstra Syndrome are described as sociable, passive, mellow, loving and outgoing. Generally the children relate better to adults than their peers and have little to no stranger anxiety. Children often prefer to observe rather then play with peers or in groups. Problem behaviours include aggression (biting, hitting, hair pulling) and unpredictable mood swings. Difficulties with  high pain tolerance, being easily frightened, feeling insecure and disliking changes in routine also lead to behaviour issues (Kleefstra Syndrome.org, Behaviours). Children with Kleefstra Syndrome are often placed on the Autism Spectrum. Due to their outgoing personality, Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS) is a common diagnosis (Belanger, 2011b).

Testing/Diagnosis 

Kleefstra syndrome can only be diagnosed through a relatively new method of genetic testing called  Fluorescence in situ hybridization or FISH (MEH Research Foundation, 2010). This testing is not available in Canada which may attribute to the lower rate of diagnosis in Canada (Belanger, 2010).

Until April 2010, this Syndrome was known as 9q34.3 deletion syndrome; After the location of the missing gene on the affected chromosome. The name was recently changed to Kleefstra Syndrome (April 2010) after Doctor Tjitske Kleefstra, a clinical geneticist in the Department of Human Genetics at Radboud University Nijmegen Medical Centre in the Netherlands (Jeans for Genes, press release). Dr. Kleefstra was the researcher who discovered the pattern in symptoms with children with this specific 9q deletion.

The majority of Kleefstra Syndrome cases are de novo or random. Only one case of transference has been documented and in that case the mother was a carrier as she has an EHMT1 mutation, not a deletion. There are no documented cases of a person with Kleefstra Syndrome reproducing (Kleefstra, T. 2009).

With the limited availability of the testing for this Syndrome, it is thought that more children may have Kleefstra Syndrome but may have received, and are being treated for, other diagnoses and/or syndromes (Belanger, 2010). Many children have lived for years with diagnoses of Angelman's Syndrome, Atypical Rhett's Syndrome and Fragile X before recently discovering they actually had Kleefstra Syndrome (Belanger, 2011).

Treatments

Early intervention is key. Early referral to age-appropriate early childhood intervention programs, special education programs, or vocational training to help the child reach his or her full potential.

Speech and Language Therapy While expressive speech may be absent or severely delayed, other forms of communication are heightened and sign language and/or a Picture Exchange Communication System may be quite successful (Kleefstra Syndrome.org, Communication). Therefore referral to Speech and Language Therapy is important.   

Physical Therapy Virtually all children with Kleefstra syndrome have low muscle tone (Hypotonia). Physical therapy provides support for a child with gross motor delays. Therapists will assist the child in building gross motor skills such as rolling, crawling, walking, and climbing stairs (Kleefstra Syndrome.org, Early Intervention). It is hoped that children with Kleefstra Syndrome will walk by the time they enter school. However, the low tone may make then tired or unable to walk long distances or stand for a great amount of time (Rare Chromosome, 12).

Occupational therapy will help develop fine motor skills as well as help the child acquire self help skills. Occupational therapy in addition to Speech therapy may help with GERD and feeding and swallowing issues. Sensory integration therapy has been successful in many cases of Kleefstra Syndrome to alleviate behaviours and help the child better integrate with their environment (Belanger, 2011).

Vision Consultation Children with Kleefstra Syndrome often have some degree of visual impairment despite having structurally typical eyes. This is called cortical visual impairment; The brain does not process accurately what the eyes are seeing. Strabismus or a squint is common, as is being near sighted. Glasses are often prescribed. Referral to a specialist with experience in children with special needs is important (Rare Chromosome, 21).

Specialized care for those with extreme behaviour problems, movement disorders, sleep disorders, epilepsy should be sought on an as needed basis. Some parents are reluctant to medicate their children for behaviour but the right medication in the right dose can be trans-formative. Puberty hormones seem to bring a sudden increase in difficult behaviours and moods. There is some recovery in adulthood but psychiatric care may be needed during the teen years. (Kleefstra Syndrome.org, Behaviour). Melatonin has been known to help the frequent night awakenings common to children with Kleefstra Syndrome. However, often families still require regular respite care (Kleefstra Syndrome.org, Sleep).  Standard treatment courses for cardiac, renal, hearing loss, and other medical issues should be prescribed by the family doctor or pediatrician. Ongoing routine monitoring by a multidisciplinary team specializing in the care of children or adults with intellectual disability, including endocrinology and a neurologist is standard (Kleefstra, T. 2010). Some families have had success with using the fundamentals of Applied Behaviour Analysis and Intensive Behaviour Intervention with their children. Often the repetitive teaching is the only way for the children to learn new tasks (Rare Chromosome, 9).

Resources

Jeans for Genes

http://www.jeansforgenes.com

Kleefstra Syndrome.org

http://www.kleefstrasyndrome.org

Rare Chromosome Support Group

http://www.rarechromo.org

Current Research

Dr. Kleefstra is currently focused on trying to answer the following question. “What function has this EHMT1 exactly during development and in the brain cells?” She states, “when we have answers to this and know the biological mechanisms causing the clinical features, we eventually hope that we can influence such a pathway by treatment some day.” (Kleefstra, T., 2011b). It is however, unlikely a treatment will be available in our generation. The focus now is on education, “We publish (case) reports in the medical literature and give presentations on international meetings, to spread knowledge on the syndrome in order to inform other medical professionals on the variation in clinical symptoms that have been observed. This will lead to a better recognition, diagnosis and optimalization of care of people with the syndrome (Kleefstra, T., 2011b).

Research in two other areas regarding Kleefstra Syndrome are also taking place. Dr. Monique Balemans has created a mouse with Kleefstra Syndrome. She is hoping to use this mouse to “look further into the mechanisms that underlie this syndrome” (Kleefstra Syndrome.org, Mouse Studies). Dr. Jamie Kramer has also developed fruit flies with Kleefstra Syndrome. Because fruit flies have similar genes as humans and their biological processes are very similar, they are a model organism for comparative research. Dr. Kramer hopes that his fruit flies will one day be able to be test subjects for future treatments for Kleefstra Syndrome (Kleefstra Syndrome.org, Fruit fly Studies)

Owen's Story 

Your child has behaviours on the Autism Spectrum, low vision, poor hearing, a heart defect, a speech delay, fine motor delay, gross motor delay, feeding concerns, immature sexual organs, cognitive delay, Gastroesophageal Reflux Disease (GERD), an umbilical hernia, hypotonia, and the list goes on and on. Doctors treat each symptom separately, no one seeing your child as a whole. As a parent you know there has to be more. It is not possible all these random factors are not linked in some way. You are not a doctor, but somehow you just know. You push for round after round of genetic testing and suddenly you have an answer. None of these symptoms are random, your child has Kleefstra Syndrome. Vindication! Your sense of elation is short lived when you discover your child is one of 124 children with this diagnosis in the world and one of only four children in Canada. No doctor in your area has heard of the diagnosis, including the geneticist who broke the news to your family. You are told to go home and research 9q deletions. The support you craved is still not there. You got your answer, but now there are just more questions. 

 

My child has Kleefstra Syndrome and this topic is very personal to me. I was told to go online and research, learn how to advocate for my son. Doctors, trained medical professionals with decades of experience, wanted me to learn about my child's diagnosis, so I could teach them. So I have and this is what I've learned. A team approach to early intervention is key. Continuing to treat my child as if he is simply a sum of his various diagnoses is not productive. Medical professionals from all fields must work together and communicate to ensure appropriate treatment in all areas of need.

Kleefstra Syndrome is a prime example of the lack of education when it comes to children with multiple diagnoses. This diagnosis, more often then not, comes only after the parents push for further testing. Doctors and therapists are only too happy to focus on their area of expertise and not look at the child as a whole. My fight was only 15 months long, but that was a year longer then it needed to be. The amazing families I have spoken with while on this journey have been fighting much longer then I have. Once doctors, therapists and families are all on the same page when it comes to care for children with special needs, our children can not help but benefit. With a little bit of education, comes hope. 

Contributed by MOM Andrea Belanger