Mirror movements are contralateral involuntary movements that mirror voluntary ones. Whereas mirror movements are occasionally found in normal young children, persistence beyond the age of 10 years is abnormal. Congenital mirror movements tend to persist throughout adulthood and ... Mirror movements are contralateral involuntary movements that mirror voluntary ones. Whereas mirror movements are occasionally found in normal young children, persistence beyond the age of 10 years is abnormal. Congenital mirror movements tend to persist throughout adulthood and tend to occur more commonly in the upper extremities (summary by Sharafaddinzadeh et al., 2008 and Srour et al., 2010). - Genetic Heterogeneity of Mirror Movements See also MRMV2 (614508), caused by mutation in the RAD51 gene (179617) on chromosome 15q15.
According to Rosemary Harvey (2008), the biographer of William Bateson (1861-1926), Bateson carried on a conversation with H. Drinkwater concerning this condition, which he referred to as bimanual synergia. The patient was a boy who seemed normal in ... According to Rosemary Harvey (2008), the biographer of William Bateson (1861-1926), Bateson carried on a conversation with H. Drinkwater concerning this condition, which he referred to as bimanual synergia. The patient was a boy who seemed normal in all respects except for the movements of his 2 hands and the sensation in his arms. He could not flex or extend the fingers of one hand without making the same movements with the other hand. Drinkwater found that the condition was hereditary and was transmitted through the mother who herself was normal. The patient's maternal aunt could control the synergic movements but only by a strong effort. The boy's brother had shown the condition in childhood but grew out of it in his early teens and recovered completely. If the boy felt a painful stimulus on one side, he immediately felt it in the same part of the other hand or arm. Drinkwater was said to have sent information on this case to the Neurological Section of the International Medical Congress meeting in London in 1913. In later correspondence, Drinkwater concluded that his pedigree of bimanual synergia did not follow mendelian rules. Sharafaddinzadeh et al. (2008) reported the 5-generation pedigree of a large Persian-speaking family from the Isfahan province of southeast Iran. There were 17 affected members of this family segregating this autosomal dominant trait with incomplete penetrance. There were far more males than females, with a 12 to 5 male-to-female ratio. All affected family members had otherwise completely normal neurologic and psychiatric examinations and brain and cervical MRI. Mirror movements were confirmed by electromyography. Srour et al. (2009) reported a 4-generation pedigree segregating autosomal dominant congenital mirror movements not associated with other neurologic abnormalities. The family was a French Canadian family originating from the Lanaudiere region of Quebec. There was no known consanguinity. Transmission was autosomal dominant with high but incomplete penetrance. Penetrance was higher in males, with a male-to-female ratio of 9 to 2. Mirror movements were present in the hands, fingers, and forearms of all affected individuals: upon voluntary activation of one hand, the contralateral hand would mirror both simple and complex movements such as writing, typing, and tapping. Three individuals reported mirror movements in the toes and feet which were observable during foot tapping and movement of the toes. In most, mirror movements were noted at birth or infancy, and persisted unchanged throughout life. Half could partially suppress the movements. Despite often high amplitude of usually observable movements, patients functioned essentially normally. One patient worked successfully as an electrician performing high precision bimanual tasks, and another worked as a secretary and could type rapidly. Three reported mild clumsiness during childhood. Several reported social impairment, stating that they felt conspicuous or embarrassed by their muscle movements. Neurologic exam was otherwise normal in all. One had a normal MRI of the brain and cervical cord. Depienne et al. (2011) reported a 3-generation Italian family in which 4 individuals had mirror movements of the arms and hands with onset in infancy or early childhood. Affected individuals had difficulty in fine bimanual movements, and 1 reported pain and muscle cramping during sustained manual activities. Only 1 patient reported some improvement during childhood; none required treatment.
Srour et al. (2010) sequenced the 29 coding exons of DCC in a French Canadian family with congenital mirror movements and identified a splice site mutation in the donor site of exon 6 (120470.0003). This exon skipping results ... Srour et al. (2010) sequenced the 29 coding exons of DCC in a French Canadian family with congenital mirror movements and identified a splice site mutation in the donor site of exon 6 (120470.0003). This exon skipping results in a frameshift and the introduction of a stop codon 15 amino acids further down the new reading frame. Srour et al. (2010) also sequenced the DCC gene in an Iranian family with congenital mirror movements, originally reported by Sharafaddinzadeh et al. (2008), and found a 1-bp insertion resulting in frameshift and truncation (120470.0004). Srour et al. (2010) proposed that DCC mutations in individuals with congenital mirror movements cause a reduction in gene dosage and less robust midline guidance, which may lead to a partial failure of axonal fiber crossing and development of an abnormal ipsilateral connection. They also concluded that DCC has a central role in the development of human nervous system lateralization. Depienne et al. (2011) identified a truncating mutation in the DCC gene (120470.0005) in an Italian family with 4 affected members.