Early infantile epileptic encephalopathy 9 (Early Infantile Epileptic Encephalopathy EIEE9) - PCDH19 gene.  

Early in September infantile epileptic encephalopathy (EIEE9), also called epilepsy restricted to women with or without mental retardation (EFMR) is a disorder characterized by seizures with onset in infancy or early childhood cognitive impairment and developmental delay . Additional features include autistic signs and psychosis. Typically, these seizures are often associated with fever, gradually increase in frequency and are accompanied by developmental regression.

This process is due to mutations in the PCDH19 gene, located on the long arm of chromosome X (Xq22.1). The protein encoded by this gene is a member of the delta-2 subclass protocadherin cadherin superfamily. It is believed that the encoded protein is a cell adhesion protein calcium dependent mainly expressed in the brain.

Several mutations have been identified in the PCDH19 gene in people with early infantile epileptic encephalopathy 9 (EIEE9) or EFMR. Some of the identified mutations lead to insertions or duplications in the PCDH19 gene (1-bp (1091_1092insC), 5-bp) resulting in a frameshift and premature termination of the protein in the extracellular domain. Other mutations result in changes or substitutions in the extracellular domain of the protein, such as V441E, Q85X and S671X. Mutations in the PCDH19 gene lead to complete loss of function of the protein, affecting the adhesive function by altering the binding of calcium.

This disease is a rare inherited pattern as it is inherited with a dominant X - linked pattern with male preservation. The gene associated with this alteration is found on the X chromosome in women, a mutation in one of the two copies of the gene in each cell is sufficient to cause disease. In males, a mutation in the single gene copy in each cell causes alteration. In the early infantile epileptic encephalopathy 9 men and women can transmit the PCDH19 mutation, although women, but men usually have symptoms. PCDH19 women with mutation have a 50% chance of having children / ace PCDH19 carriers. Males however have a 100% chance of passing the mutation if they have daughters and no chance if they have children.

Tests in IVAMI: in IVAMI perform detection of mutations associated with early infantile epileptic encephalopathy 9 (EIEE9), by complete PCR amplification of the exons of the PCDH19 gene, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).