OMIM ID:
Nystagmus 5, Congenital, X-linked
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
In the single 4 generation French family reported nystagmus was the only ocular finding. It is present at birth or within the first year of life. Visual acuity has not been reported.
Systemic Features
None reported.
Genetics
Inheritance
The pattern of inheritance is uncertain. Both sexes may be affected but no male-to-male transmission was documented in the single family reported. Apparent incomplete penetrance makes analysis difficult since several unaffected females transmitted the phenotype to male offspring.
No mutation has been identified but a possible locus within Xp11.4-p11.3 may contain the mutant gene.
Autosomal dominant transmission patterns have been reported in other families: NYS2, NYS3, NYS4, and NYS7.
This database contains several additional forms of congenital nystagmus inherited in X-linked recessive patterns: NYS1, and NYS6.
Pedigree
X-linked dominant, mother affected
X-linked inheritance patterns result from mutations located on the X chromosome. Females have two X chromosomes of which only one carries a mutation in X-linked dominant disorders. This usually results in expression of the disease and women with a single mutation have the disorder caused by the mutation. Half of their offspring, male and female, will inherit the mutation. Men, with only one X chromosome, will always have the condition if they inherit the one with the mutation. Men would transmit it to all of their offspring. Without a modifying normal gene on a second X chromosome, X-linked dominant conditions are frequently lethal in such males. The result is a vertical transmission pattern, usually from female to female.
X-linked inheritance patterns result from mutations located on the X chromosome. Females have two X chromosomes of which only one carries a mutation in X-linked dominant disorders. This usually results in expression of the disease and women with a single mutation have the disorder caused by the mutation. Half of their offspring, male and female, will inherit the mutation. Men, with only one X chromosome, will always have the condition if they inherit the one with the mutation. Men would transmit it to all of their offspring. Without a modifying normal gene on a second X chromosome, X-linked dominant conditions are frequently lethal in such males. The result is a vertical transmission pattern, usually from female to female.