Best's vitelliform macular dystrophy caused by a new mutation (Val89Ala) in the VMD2 gene.
OBJECTIVE
To describe the clinical phenotype in a family with Best's vitelliform macular dystrophy (BMD) and a new mutation (Val89Ala) in the VMD2 gene.


METHODS
The genotype was determined by direct sequence analysis of the individual exons of VMD2. Nine members of a family with BMD were examined. The examination included best-corrected visual acuity, electro-oculography (EOG), fundus examination, and photography. Four of the patients were also examined with full-field ERG and three with multifocal ERG.


RESULTS
A T-to-C substitution was identified at position 370 in the cDNA of VMD2, leading to a Val89Ala change in the protein. Six patients, five with the Val89Ala mutation and a nine-year-old boy without the mutation, presented with a pathological Arden ratio on EOG examination. Most of the patients with BMD in this family had an onset of visual failure by the age of 40-50 years. The older patients in the family demonstrated atrophic macular dystrophy.


CONCLUSIONS
Patients with BMD and the Val89Ala mutation in the VMD2 gene can present with a phenotype of a mostly late-onset visual failure. These BMD patients, who present with visual failure and macular degeneration in middle age, can be misdiagnosed as being affected with adult-onset macular dystrophies instead of BMD, because the latter is often regarded as a disease of childhood and adolescence.
Eksandh
L
L
Department of Ophthalmology, University Hospital, Lund, Sweden. louise.eksandh@telia.com
Bakall
B
B
Bauer
B
B
Wadelius
C
C
Andréasson
S
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000075002:Bestrophins; D002648:Child; D018118:Chloride Channels; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004252:DNA Mutational Analysis; D004585:Electrooculography; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D014792:Visual Acuity
C113133:BEST1 protein, human; D000075002:Bestrophins; D018118:Chloride Channels; D005136:Eye Proteins; D004247:DNA