Microcephaly, seizures, spasticity, and brain calcifications (MISSBC) is a genetic neurodevelopmental disorder characterized by microcephaly (abnormally small head), early-onset seizures, and delayed or absent psychomotor/mental development.
Symptoms of MISSBC may include microcephaly, spasticity/dystonia (abnormal muscle tone or tightness), seizures involving muscle jerks or violent convulsions at a young age, and delays in developmental milestones such as walking, rolling over, talking, or learning social cues like making eye contact or a social smile.
MISSBC is caused by a mutation in the PCDH12 gene found on chromosome 5. Genes are units of DNA passed down in families that create proteins responsible for normal bodily/cellular processes. When a gene is mutated, the proteins and processes are disrupted. The PCDH12 gene is passed down in an autosomal recessive pattern, meaning both parents must have the mutated gene for their offspring to develop MISSBC.
Symptoms of MISSBC may be diagnosed prenatally (before birth) through examination of the fetus via an ultrasound, which can indicate microcephaly and other abnormalities. Other symptoms may be diagnosed postnatally (following birth) by examining social/development patterns and looking at images of the brain (taken with EEGs and MRIs). Genetic testing may be available to confirm the PCDH12 genetic mutation.
There is no treatment for MISSBC, but some symptoms may be managed individually. Antiepileptic/anticonvulsant medication may be prescribed to control seizures, and speech, language, or behavior therapy may be options for those seeking to address developmental/social delays.
If you or a family member has been diagnosed with MISSBC speak with your doctor to learn more information. Support groups may also be available for further resources.
Description Last Updated: Aug 22, 2018