5q14.3 microdeletion syndrome [Del(5)(q14.3)] is a disorder characterized by severe intellectual/mental disability, epilepsy, an inability to speak, and stereotypic movements (repetitive, nonfunctional behavior, such as hand waving or head banging).
Symptoms of Del(5)(q14.3) may include intellectual disability, delayed speech development, low muscle tone, poor eye contact, stereotypic movements, and abnormal facial features like a high, broad forehead and small chin, a short nose and front-facing nostrils, down-turned eyes, and prominent eyebrows. Epilepsy is also common – seizures caused by fever, involving involuntary muscle jerks, and those with violent convulsions have all been reported. Epileptic symptoms may start as early as infancy, and developmental milestones like walking may be delayed.
Del(5)(q14.3) is heritable (passed on in families), and is caused by a “deletion” mutation in the MEF2C gene on chromosome 5. Genes are units of DNA passed from parent to child that regulate normal bodily/cellular processes. The MEF2C gene is inherited in an autosomal dominant pattern, meaning only one parent needs to have the mutation for their offspring to display symptoms.
Diagnosis of Del(5)(q14.3) usually occurs in early childhood through observations of physical/behavioral development, though it may be misdiagnosed as an autism spectrum disorder. MRIs or EEGs may be done to detect abnormal brain activity caused by seizures. Genetic testing may be done to confirm the MEF2C deletion mutation.
There is no cure for Del(5)(q14.3); however, symptoms can be managed. Epilepsy may be treated with antiseizure medication, and developmental disabilities may be managed through speech therapy and guided social interaction. Genetic counseling may be available for families affected by Del(5)(q14.3). If you or a family member have been diagnosed with Del(5)(q14.3), speak with your doctor to learn more information.
Description Last Updated: Aug 05, 2018