Clinical features of de novo GRIN1 mutations include infantile involuntary movements, seizures, and hand stereotypies, suggesting that GRIN1 mutations cause encephalopathy resulting in seizures and movement disorders.
GNAL mutations have been shown to cause adult-onset isolated dystonia, a disabling movement disorder characterized by involuntary muscle contractions causing twisting and repetitive movements or abnormal postures.
The transcription factor THAP1 (THanatos Associated Protein 1) has emerged recently as the cause of DYT6 primary dystonia, a type of rare, familial and mostly early-onset syndrome that leads to involuntary muscle contractions.
All affected members present with cognitive impairment and two of them with mild intermittent involuntary movements in association with the clinical hallmarks of SCA15 (gait ataxia, balance impairment, and dysarthria).
Schizophrenia patients who carry the dopamine D3gly allele and the cytochrome P 450 17alpha-hydroxylase A2-A2 genotype may be more likely to develop abnormal orofoacial and distal involuntary movements and to be incapacitated by these movements when chronically exposed to classical antipsychotic drugs.
Humans with heterozygous mutations in the axon guidance receptor DCC display congenital mirror movements (MMs), which are involuntary movements of body parts, such as fingers, on one side of the body that mirror voluntary movement of the opposite side.
In addition, a recent clinical study demonstrated that a missense mutation in the SV2A gene caused intractable epilepsy with involuntary movements and developmental retardation, illustrating a causative role of SV2A dysfunction in epilepsy.
Here, we have identified 3 mutations in exon 7 of NTN1 in 2 unrelated families and 1 sporadic case with isolated congenital mirror movements (CMM), a disorder characterized by involuntary movements of one hand that mirror intentional movements of the opposite hand.
Three sporadic patients (two men and one woman) were examined with involuntary movements and dysarthria associated with abnormal concentrations of serum copper, serum ceruloplasmin, and urinary copper excretion.