Nystagmus 7, Congenital, AD
Patient Information
Characteristics
Background and History
Nystagmus, sometimes called ‘dancing eyes’ comes in many forms and has multiple causes. It may result from other eye disease or from more general neurological conditions. When present at birth (congenital), it is usually inherited in one of several patterns. Usually there is some reduction in vision since patients are unable to focus steadily on objects.
Clinical Correlations
Several Chinese families with this condition were reported in 2012. The eyes were noted in infancy to have a pendular movement. No other ocular or systemic abnormalities were present. The level of vision was not reported.
Genetics
Inheritance
The pattern of patients with this eye movement disorder in the reported pedigrees suggests autosomal dominant inheritance. No gene mutation has been found but a location on chromosome 1 was considered likely to contain the responsible gene. Parents with this form of nystagmus could expect that half of their children will have the same condition.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission
Diagnosis and Prognosis
As in other forms of nystagmus, it is likely that the abnormal eye movements would be diagnosed by a pediatrician or eye doctor. Nothing is known about the prognosis or the level of visual functioning but since individuals were otherwise healthy, a normal lifespan could be expected.
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