Nystagmus 6, Congenital, X-linked

Clinical Characteristics
Ocular Features: 

In several Chinese families, nystagmus was limited to males with onset in one case in the first 6 months.  Foveal dysplasia was present along with mottled fundus pigmentation.  Carrier females did not have nystagmus or changes in fundus pigmentation (except for one with mottling). Vision is in the range of 20/50-20/60.

Systemic Features: 

Skin and hair pigmentation was normal. No systemic disease was identified.

Genetics

Mutations in GPR143 (Xp22.2) have been identified in this form of nystagmus. The family pedigrees are consistent with X-linked recessive inheritance.

Two additional X-linked isolated nystagmus conditions are contained in this database: nystagmus 1 (310700), the result of mutations in FRMD7, and nystagmus 5 (300589) of unknown gene causation.

Several autosomal dominant forms have been linked to chromosomal regions 6p12 (NYS2; 164100), 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).

Ocular albinism (OA1) (300500) can also result from mutations in GPR143.  However, there was no evidence of ocular or systemic hypopigmentation in the Chinese families.

Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Aprataxin gene mutations in Tunisian families

Amouri R, Moreira MC, Zouari M, El Euch G, Barhoumi C, Kefi M, Belal S, Koenig M, Hentati F. Aprataxin gene mutations in Tunisian families. Neurology. 2004 Sep 14;63(5):928-9.

PubMed ID: 
15365154

References

Liu J, Jia Y, Wang L, Bu J. A previously unidentified deletion in G protein-coupled receptor 143 causing X-linked congenital nystagmus in a Chinese family. Indian J Ophthalmol. 2016 Nov;64(11):813-817.

PubMedID: 27958203

Kim US, Cho E, Kim HJ. A novel nonsense mutation of GPR143 gene in a Korean kindred with X-linked congenital nystagmus. Int J Ophthalmol. 2016 Sep 18;9(9):1367-70.

PubMedID: 27672609

Han R, Wang X, Wang D, Wang L, Yuan Z, Ying M, Li N. GPR143 Gene Mutations in Five Chinese Families with X-linked Congenital Nystagmus. Sci Rep. 2015 Jul 10;5:12031.

PubMedID: 26160353

Peng Y, Meng Y, Wang Z, Qin M, Li X, Dian Y, Huang S. A novel GPR143 duplication mutation in a Chinese family with X-linked congenital nystagmus. Mol Vis. 2009;15:810-4.

PubMedID: 19390656

Zhou P, Wang Z, Zhang J, Hu L, Kong X. Identification of a novel GPR143 deletion in a Chinese family with X-linked congenital nystagmus. Mol Vis. 2008 May 30;14:1015-9.

PubMedID: 18523664

Liu JY, Ren X, Yang X, Guo T, Yao Q, Li L, Dai X, Zhang M, Wang L, Liu M, Wang QK. Identification of a novel GPR143 mutation in a large Chinese family with congenital nystagmus as the most prominent and consistent manifestation. J Hum Genet. 2007;52(6):565-70.

PubMedID: 17516023

Amouri R, Moreira MC, Zouari M, El Euch G, Barhoumi C, Kefi M, Belal S, Koenig M, Hentati F. Aprataxin gene mutations in Tunisian families. Neurology. 2004 Sep 14;63(5):928-9.

PubMedID: 15365154