logo Click here for the MAMMAG Home Page Click here for the UC Irvine Home Page Click here for the School of Medicine Home Page
 
 
 
 

4008: OPA-3 OPTIC ATROPHY 3

Order this test

Test Code Test Name Turnaround Blood Sample Tissue Sample CPT Codes 2015 CPT Codes 2013
4008 OPA-3 3 weeks $430.00 $530.00 81404 81479
(Optic Atrophy 3) gene Sequencing entire coding region

Selecting the Appropriate Sample Type

*Testing Method: Sequencing of the OPA3 gene. Nuclear gene testing is most commonly performed using blood samples, but other sample types will be accepted.

Autosomal dominant optic atrophy (DOA) is one of the most common genetic causes of blindness. The majority of DOAs are caused by mutations in OPA1, resulting in the degeneration of retinal ganglion cells, reduced visual acuity, color vision abnormalities, centrocaecal visual field defects and pallor of the optic nerve head. OPA1 is a nuclear gene and encodes an inner mitochondrial membrane protein. The protein consists of an N-terminal mitochondrial targeting signal, a transmembrane domain, presenilin-associated rhomboid-like protease recognition sites and a dynamin-like domain with GTP-binding activity. It plays an important role in mitochondrial fusion, apoptosis, ATP production and reactive oxygen species (ROS) production.

Optic atrophy 3 is a subtype of optic atrophy, also inherited in an autosomal dominant manner. Besides optic atrophy, patients also present with cataract, and a neurologic disorder such as extrapyramidal signs and ataxia. Inheritance was clearly autosomal dominant. Cataract was often recognized in the first decade. OPA3 is on chromosome 19q13.32 and mutations of OPA3 cause this condition.1

Mutations of OPA3 also cause 3-methylglutaconic aciduria type III (MGCA3). 2 Type III 3-methylglutaconic aciduria is also called Costeff syndrome with a clinical feature of neuroophthalmologic syndrome early-onset bilateral optic atrophy and later-onset spasticity, extrapyramidal dysfunction, and cognitive deficit. Urinary excretion of 3-methylglutaconic acid and of 3-methylglutaric acid is increased.2. The phenotype is similar to Behr syndrome and may in some cases represent the same disorder.3

References

1. Reynier P, Amati-Bonneau P, Verny C, Olichon A, Simard G, Guichet A, Bonnemains C, Malecaze F, Malinge MC, Pelletier JB, Calvas P, Dollfus H, Belenguer P, Malthiery Y, Lenaers G, Bonneau D (2004) OPA3 gene mutations responsible for autosomal dominant optic atrophy and cataract. J Med Genet 41:e110

2. Anikster Y, Kleta R, Shaag A, Gahl WA, Elpeleg O (2001) Type III 3-methylglutaconic aciduria (optic atrophy plus syndrome, or Costeff optic atrophy syndrome): identification of the OPA3 gene and its founder mutation in Iraqi Jews. Am J Hum Genet 69:1218-1224

OMIM: 165300