Which are the symptoms of Koolen De Vries Syndrome / 17q21.31 Microdeletion Syndrome?

Koolen De Vries Syndrome (KdVS) / 17q21.31 Microdeletion Syndrome is a rare genetic disorder caused by a deletion of a small piece of genetic material on chromosome 17. This deletion affects the 17q21.31 region, leading to a variety of physical and developmental symptoms. Individuals with KdVS may exhibit a range of symptoms, but it's important to note that the severity and specific manifestations can vary widely from person to person.

Intellectual disability: One of the most common features of KdVS is intellectual disability. Individuals with this syndrome typically have mild to moderate intellectual impairment, although the severity can vary. Learning difficulties, delayed speech and language development, and challenges with abstract thinking and problem-solving are often observed.

Distinctive facial features: Many individuals with KdVS have characteristic facial features that may include a high forehead, a broad and prominent nasal bridge, widely spaced eyes (hypertelorism), long and smooth philtrum, and a thin upper lip. These facial characteristics can be subtle and may become more apparent with age.

Developmental delays: Children with KdVS often experience delays in reaching developmental milestones. Motor skills, such as sitting, crawling, and walking, may be delayed. Speech and language development may also be affected, with delayed or limited vocabulary and difficulties with articulation.

Behavioral and psychiatric issues: Individuals with KdVS may exhibit behavioral and psychiatric issues, including hyperactivity, attention deficit hyperactivity disorder (ADHD), anxiety, and autistic-like behaviors. Some individuals may also have difficulties with social interactions and exhibit repetitive behaviors.

Seizures: Epilepsy and seizures are relatively common in individuals with KdVS. The type and frequency of seizures can vary, ranging from mild to severe. It is important for individuals with KdVS to receive appropriate medical management and seizure monitoring.

Physical abnormalities: Some individuals with KdVS may have physical abnormalities, such as low muscle tone (hypotonia), joint hypermobility, and skeletal abnormalities. These physical features can contribute to motor delays and difficulties with coordination.

Heart defects: Approximately one-third of individuals with KdVS have congenital heart defects. These can include abnormalities in the structure or function of the heart, such as atrial or ventricular septal defects, patent ductus arteriosus, or abnormalities of the heart valves. Regular cardiac evaluations are important for individuals with KdVS.

Growth and feeding difficulties: Some individuals with KdVS may experience growth delays, resulting in short stature. Feeding difficulties, such as poor weight gain, swallowing difficulties, and gastroesophageal reflux, may also be present in infancy and early childhood.

Hearing and vision problems: Hearing loss, both conductive and sensorineural, can occur in individuals with KdVS. Vision problems, such as refractive errors, strabismus (crossed eyes), and nystagmus (involuntary eye movements), may also be present.

Other features: Additional features that have been reported in individuals with KdVS include kidney abnormalities, genital abnormalities, dental issues, and susceptibility to infections.

It is important to note that not all individuals with KdVS will exhibit all of these symptoms, and the severity of each symptom can vary. Early diagnosis and appropriate management, including early intervention services, educational support, and medical care, can greatly improve the quality of life for individuals with KdVS and their families.