Main clinical features caused by mutations in the CNNM2 gene are:
- Hypomagnesemia (serum magnesium levels <0.7 mmol/L)
- Intellectual disability
- Infantile/juvenile refractory epilepsy
- Communication/speech limitations
- Fine motor skill defects
- Muscle cramps
- Obesity
- Brain malformations, including myelinization defects and enlarged liquor spaces (only observed in patients with autosomal recessive inheritance)