An atypical form of Bietti crystalline dystrophy

Ophthalmic Genet. 2011 Jun;32(2):118-21. doi: 10.3109/13816810.2011.559653. Epub 2011 Mar 8.


Purpose: To describe clinical and functional features of a patient with Bietti crystalline dystrophy and atypical electroretinogram responses.

Methods: The patient underwent a thorough medical anamnesis, genetic counseling, peripheral blood draw for CYP4V2 gene analysis and electron microscopy, and a complete ophthalmological assessment including optical coherence tomography, indocyanine green angiography, microperimetry, full-field electroretinogram and multifocal electroretinogram.

Results: The most striking features of the retina were deposits of yellowish-white glistening crystals and focal lobular areas of choriocapillary atrophy at the posterior pole and midperiphery. The full-field electroretinogram was normal and the multifocal electroretinogram showed extinguished central recordings. Mutation analysis revealed a homozygous c. 332T>C p.I111T mutation in exon 3 of the CYP4V2 gene. Typical cytoplasmic inclusions containing crystalline-like structure and large degenerative lysosomes were seen on electron microscopy of peripheral leukocytes.

Conclusion: Here we describe a patient with Bietti crystalline dystrophy with a CYP4V2 gene mutation and typical leukocyte inclusions who showed the classical retinal lesions but had a normal electroretinogram. This suggests the existence of less severe forms of BCD related to relatively mild CYP4V2 mutations.

Publication types

  • Case Reports

MeSH terms

  • Corneal Dystrophies, Hereditary / diagnosis
  • Corneal Dystrophies, Hereditary / genetics
  • Cytochrome P-450 Enzyme System / genetics*
  • Cytochrome P450 Family 4
  • DNA Mutational Analysis
  • Electroretinography
  • Fluorescein Angiography
  • Humans
  • Inclusion Bodies / genetics
  • Inclusion Bodies / pathology
  • Indocyanine Green
  • Leukocytes / pathology
  • Male
  • Middle Aged
  • Mutation*
  • Night Blindness / diagnosis
  • Night Blindness / genetics
  • Pedigree
  • Retinal Diseases / diagnosis
  • Retinal Diseases / genetics
  • Retinal Pigment Epithelium / pathology
  • Tomography, Optical Coherence
  • Visual Field Tests
  • Visual Fields / physiology


  • Cytochrome P-450 Enzyme System
  • CYP4V2 protein, human
  • Cytochrome P450 Family 4
  • Indocyanine Green

Supplementary concepts

  • Bietti Crystalline Dystrophy