Study on epilepsy, neurodevelopmental disorder, and motor disorders associated with mutations in the DHDDS gene

Goal of Study: Look at the role of DHDDS (dehydrodolichyl diphosphate synthase) and its mutations in the onset of developmental delay and seizures, with or without movement abnormalities. 

Important elements:

• The genotype-phenotype characteristics are still inconclusive 

• This study analyzed the characteristics of epilepsy, and neurodevelopmental and motor disorders related to DHDDS gene mutations and reported the genotype-phenotype characteristics of a child with DHDDS

Methods of Study:

• Reviewed literature relevant of DHDDS gene mutations

• Total of 25 cases were retrieved for the study 

• Characteristics of the DHDDS gene were summarized and analyzed 

Results of Study:

• Onset of epilepsy caused by the DHDDS gene mutation typically occurs during infancy

• The initial manifestation of epilepsy is typically seen as quick, involuntary muscle jerks (myoclonus)

• The onset of epilepsy frequently coexists with neurodevelopmental disorder and intellectual disability, however individuals have no specific type of motor disorder

• MRI imaging revealed no abnormalities, whereas EEG frequently exhibits abnormalities

• Valproic acid (VPA), a type of medication for epilepsy, showed curative effects

Conclusion of Study:

• Mutations in the DHDDS gene are associated with congenital glycosylation disorder (CDG), autosomal recessive retinitis pigmentosa, and epilepsy

• CDG is a large group of rare genetic disorders that affect the addition of sugar building blocks, called glycans, to proteins in cells throughout the body (additional of glycans to proteins is vital to healthy function of cells)

• Retinitis pigmentosa is an inherited vision disorder that can cause progressive deterioration of the retina. It is consider autosomal recessive because while it is a genetic condition passed down through the parents, the child is the only one of the actual condition

• VPA typically produced beneficial therapeutic results and differences statistically significant