Early infantile epileptic encephalopathy-9 (EIEE9) first reported as epilepsy and mental retardation limited to females (EFMR)  is a rare epilepsy syndrome caused by a  mutation of the PCDH19 gene found on the X chromosome. Males who carry the gene  mutation on their only X chromosome are typically not affected. In contrast, 90% of women who have the PCDH19 gene mutation on one of their two X chromosomes have the symptoms.

The clinical picture is heterogeneous, but epilepsy onset in infancy, fever sensitivity and occurrence of seizures in clusters are key features. Seizures remit in the majority of patients during teenage years. Intellectual disability and behavioural disturbances are common.

OBJETIVES

Describe the phenotypic spectrum of a family affected by PCDH19 gene mutated.

MATERIALS AND METHODS

Female patient, 10 years old, 3rd daughter of non-consanguineous parents. It starts with seizures at 9 months of age, most of them associated with fever.

Family history is presented as women by paternal branch affected with epilepsy and other neurological deficits.

CONCLUSION

EIEE9 is transmitted via asymptomatic males, suggesting an unusual X-linked inheritance with selective involvement of females. The molecular confirmation of the genetic defect and an analysis of the parents’ status are crucial to be able to give families appropriate genetic counseling.

Given the unusual mode of inheritance and the wide phenotypic variability associated with PCDH19 mutations, genetic counseling appears delicate. In the case of mutations inherited from an asymptomatic father, all the daughters are expected to be affected.