What is Koolen-de Vries syndrome (KDVS)?
Koolen-de Vries syndrome is a rare genetic condition believed to occur in 1 in every 55,000 people. It is a recently discovered condition and was first identified in 2006.
Characteristic features of the syndrome include mild-moderate intellectual disability with developmental delay. Low muscle tone in childhood is also a defining symptom of the syndrome.
Individuals with the syndrome are often described as having a sociable, happy personality.
Syndrome Synonyms:
Chromosome 17q21.31 Deletion Syndrome; Microdeletion 17q21.31 Syndrome
What gene change causes Koolen-de Vries syndrome (KDVS)?
The syndrome is caused by either a microdeletion of a small part of chromosome 17, or by a mutation of the KANSL1 gene.
The deletions or mutations that cause the syndrome are random and the majority of individuals are the first in their family with the syndrome.
Microdeletion inheritance occurs when there is a deletion of several genes on a chromosome. The specific chromosome on which the deletions occur will determine the syndrome they cause.
In some cases, a genetic syndrome may be the result of a de-novo mutation and the first case in a family. In this case, this is a new gene mutation which occurs during the reproductive process.
What are the main symptoms of Koolen-de Vries syndrome?
Facial and physical characteristics include a pear-shaped nose, long face, broad forehead, droopy eyelids and very prominent ears.
Other health conditions may include epilepsy, estimated to be a major symptom in 50% of individuals diagnosed with the syndrome.
Heart defects, kidney disease, and bone abnormalities are also recognized symptoms in some affected individuals.
Possible clinical traits/features:
Wide nasal bridge, Cataract, Bulbous nose, Abnormal cardiac septum morphology, Abnormal aortic valve morphology, Aortic dilatation, Arachnodactyly, Atrial septal defect, Aplasia/Hypoplasia of the corpus callosum, Bicuspid aortic valve, Blepharophimosis, Cleft palate, Hypopigmentation of hair, Underdeveloped nasal alae, Generalized hypotonia, Cognitive impairment, Global developmental delay, Ichthyosis, Hypotrophy of the small hand muscles, Delayed speech and language development, Hypothyroidism, Hypotelorism, Broad forehead, Prominent nasal bridge, Hip dysplasia, Hydronephrosis, High palate, High forehead, High, narrow palate, Nasal speech, Hypermetropia, Kyphosis, Short stature, Scoliosis, Spondylolisthesis, Vertebral fusion, Upslanted palpebral fissure, Strabismus, Anteverted ears, Broad chin, Ptosis, Microcephaly, Reduced number of teeth, Prominent metopic ridge, Wide intermamillary distance, Pyloric stenosis, Variable expressivity, Sporadic, Ventricular septal defect, Pulmonic stenosis, Contiguous gene syndrome.
How is it diagnosed?
To find out if someone has a diagnosis of Koolen-de Vries syndrome, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
