TUBB4B

Leber Congenital Amaurosis with Early-Onset Deafness

Clinical Characteristics
Ocular Features: 

Evidence for retinal disease can be seen within 3 years of age.  Three of 5 patients had no detectable responses on the ERG when tested at birth.  A 34-year-old female was noted to have advanced retinitis pigmentosa with attenuation of retinal vessels, choroidal atrophy, peripheral pigmentary deposits, and macular anomalies.  The posterior fundus may have a salt-and-pepper pigmentation.  Hypermetropia was present in all 5 patients.

Visual acuity varies widely and may be normal even among older patients.

Systemic Features: 

Mild to severe sensorineural hearing loss secondary to cochlear cell loss is usually diagnosed in the first decade.  All patients had normal neuro-psychomotor development.

Genetics

Heterozygous mutations in the TUBB4B gene (9q34.3) have been found in 5 individuals in 4 families with this disorder.  There may be significant mosaicism in blood cells.

See Leber Congenital Amaurosis for additional information on non-syndromal Leber congenital amaurosis and responsible mutations.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No treatment is available for the general condition but refractive correction, low vision aids, and assistive hearing devices may be of benefit.

References
Article Title: 

Mutations in TUBB4B Cause a Distinctive Sensorineural Disease

Luscan R, Mechaussier S, Paul A, Tian G, Gerard X, Defoort-Dellhemmes S, Loundon N, Audo I, Bonnin S, LeGargasson JF, Dumont J, Goudin N, Garfa-Traore M, Bras M, Pouliet A, Bessieres B, Boddaert N, Sahel JA, Lyonnet S, Kaplan J, Cowan NJ, Rozet JM, Marlin S, Perrault I. Mutations in TUBB4B Cause a Distinctive Sensorineural Disease. Am J Hum Genet. 2017 Dec 7;101(6):1006-1012.

PubMed ID: 
29198720
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