OMIM ID:
Nystagmus 2, Congenital, AD
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
Pendular and sometimes jerk nystagmus are often present at birth. Other patients are diagnosed between 3 and 6 months. Vision is usually stable in the range of 20/30 to 20/100 with most patients having 20/50. Between 35% and 50% of individuals have strabismus as well.
Systemic Features
None have been reported.
Genetics
Inheritance
Familial cases have an autosomal dominant transmission pattern. No specific mutation has been found but strong linkage with a region at 6p12 has been reported.
Several additional autosomal dominant forms of congenital nystagmus have been linked to chromosomal regions 7p11 (NYS3, 608345), 13q (NYS4, 193003), 1q31.3-q32.1, and NYS7 (614826). Autosomal recessive inheritance has been proposed for several pedigrees but adequate documentation is lacking (see 257400).
This database also contains 3 types of congenital nystagmus inherited in X-linked recessive patterns: 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