Families

Clinical features
Individuals with PCYT2-associated disorders can have a variable clinical phenotype, including rigidity of the limbs, developmental delay, intellectual disability and epilepsy. MRI studies showed progressive cerebral atrophy and white matter hyperintensities. Visual impairment with cataracts, abnormal ocular movements and optic atrophy or skeletal abnormalities have also been reported in these patients.

Prevalence
The prevalence of PCYT2-associated disorders cannot be ascertained because of the limited number of cases identified to date (less than 20 patients worldwide to date).

Inheritance
The disease is inherited in an autosomal recessive manner: this means that both copies of the PCYT2gene must be mutated in an individual to be affected, whereas heterozygotes (with only one mutated copy) are asymptomatic carriers and thus do not manifest the condition but are at risk of transmitting it. Parents of a patient are usually carriers of the mutations and they have a 25% chance to have other children affected. Therefore, a genetic counselling and testing at risk family members are crucial for these families.