OMIM ID:
Nystagmus 7, Congenital, AD
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
A pendular nystagmus is usually diagnosed in infancy. The eye is otherwise anatomically and functionally normal. No photophobia, hypopigmentation, night blindness have been noted in the two Chinese families reported. The ERG and foveal appearance are normal. Visual acuity has not been reported.
Systemic Features
No systemic abnormalities have been found.
Genetics
Inheritance
The two reported multigenerational pedigrees show a pattern consistent with autosomal dominant inheritance. No causative mutation has been identified but mapping suggests a locus at 1q31-q32.2 that segregates with the condition.
Nystagmus 2 (164100), nystagmus 3 (608345), and nystagmus 4 (614826) are other autosomal dominant forms of simple nystagmus but they are unique disorders as they map to other chromosomal locations.
Several forms of X-linked recessive inheritance are contained in this database: NYS1, NYS5, and NYS6.
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