BCD Prevalence

BCD is an often-misdiagnosed retinal disease.
BCD is an often-misdiagnosed retinal disease

BCD Prevalence

While Bietti’s Crystalline Dystrophy (BCD) is generally considered to be a rare disease, it may be underdiagnosed. For example, in a study done by Mataftsi et al 2004, approximately 10% of persons with autosomal recessive retinitis pigmentosa (RP) were also diagnosed with BCD. Furthermore, it has been estimated that up to 3% of individuals initially diagnosed with RP can be accounted for by BCD Mataftsi et al 2004. According to Hartong et al 2006, worldwide prevalence of RP was one in 4,000, with autosomal recessive RP accounting for 50%-60% of the affected individuals. This implies a prevalence of BCD of up to 1:67,000, representing almost 5,000 individuals in the US alone.

BCD appears to be more common in people of East Asian descent, particularly the Chinese and Japanese Hu 1983, Tian et al 2015; however, individuals of European, Middle Eastern, African, and North and South American origin have also been reported Mataftsi et al 2004, Lin et al 2005, Lai et al 2007, Zenteno et al 2008, García-García et al 2013, Astuti et al 2015.

Source:

Vargas M, Mitchell A, Yang P, et al. Bietti Crystalline Dystrophy. 2012 Apr 12 [Updated 2019 Feb 7]. In: Adam MP, Ardinger HH, Pagon RA, et al., editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2020. Available from: https://www.ncbi.nlm.nih.gov/books/NBK91457/

BCD Worldwide Genetic Prevalence

Table: Worldwide carrier frequency of CYP4V2 mutations and genetic prevalence of biallelic cases

Population Population size Carrier frequency Total number of carriers Genetic prevalence Total number of biallelic cases Top 3 CYP4V2 mutations and
carrier frequency
African
1,340,598,113
1:291
4,603,731
1:332,661
4,030
c.987+3A>G: 1.87E-03
c.990del , p.His331Thrfs*8: 1.39E-04
c.1355G>A , p.Arg452His: 2.11E-04
East Asian
1,678,089,627
1:90
18,743,394
1:32,014
52,417
c.802-8_810del17insGC: 3.27E-03
c.992A>C , p.His331Pro: 1.70E-03
c.1091-2A>G: 9.29E-04
European
742,095,327
1:277
2,675,220
1:301,508
2,461
c.130T>A , p.Trp44Arg: 3.96E-04
c.400G>T , p.Gly134*: 5.98E-04
c.1198C>T , p.Arg400Cys: 2.43E-04
Finnish
5,540,718
1:257
21,598
1:263,566
21
c.1A>G , p.Met1?: 2.84E-04
c.414-1G>A: 2.81E-03
c.1167del , p.Arg390Alafs*25: 5.60E-04
Latino
653,962,332
1:164
3,978,575
1:108,064
6,052
c.130T>A , p.Trp44Arg: 2.05E-03
c.254G>A , p.Arg85His: 1.77E-03
c.1338del , p.Glu447Argfs*22: 6.02E-04
South Asian
1,940,369,605
1:566
3,427,060
1:1,282,417
1,513
c.197T>G , p.Met66Arg: 6.39E-04
c.1169G>A , p.Arg390His: 1.19E-04
c.1199G>A , p.Arg400His: 2.82E-04
Worldwide
7,794,798,729
1:210
37,123,684
1:116,051
67,167
Source:
Hanany M, Yang RR, Lam CM, Beryozkin A, Sundaresan Y, Sharon D. An in-depth single-gene worldwide carrier frequency and genetic prevalence analysis of CYP4V2 as the cause of Bietti crystalline dystrophy. Transl Vis Sci Technol. 2023;12(2):27, https://doi.org/10.1167/tvst.12.2.27