Molecular Vision: Zhao, Mol Vis 2025; 31:256-265. Table 2

Table 2. Summary of CYP4V2 mutation types in BCD patients.

Study	Mutation	Type	Population	Frequency	Clinical/Experimental Findings	Reference
Meng et al. (2014)	c.802_810del17insGC	Insertion-deletion	Chinese	Most prevalent	- Severe retinal dysfunction - Early onset crystalline deposits - Significant chorioretinal atrophy	[12]
Meng et al. (2014)	p.Tyr343Asp	Missense	Chinese	Common	- Moderate retinal dysfunction - Variable age of onset	[12]
Meng et al. (2014)	p.Gln11X	Nonsense	Chinese	Rare	- Severe phenotype - Early onset	[12]
Yin et al. (2016)	c.802–8_810del17bpinsGC	Complex	Chinese	0.375	- Progressive vision loss - Extensive RPE atrophy - Choroidal sclerosis	[13]
Yin et al. (2016)	c.992A>C (p.H331P)	Missense	Chinese	0.194	- Moderate disease progression - Variable crystalline deposits	[13]
Yin et al. (2016)	c.1091–2A>G	Splice-site	Chinese	0.141	- Abnormal splicing - Moderate to severe phenotype	[13]
Yin et al. (2016)	c.65T>A (p.L22H)	Missense (Novel)	Chinese	Single family	- Early onset - Rapid progression - Affects protein stability	[13]
Yin et al. (2016)	c.681_4delTGAG (p.S227Rfs*1)	Frameshift (Novel)	Chinese	Single family	- Severe phenotype - Protein truncation - Early onset	[13]
Jiao et al. (2017)	Multiple missense mutations	Missense (68%)	Mixed	68% of total	- Variable expressivity - Age-dependent penetrance	[14]
Guo et al. (2019)	c.802–8_810del17bp	Complex	Chinese Han	0.412	- Severe chorioretinal atrophy - Early crystalline deposits - Poor visual prognosis	[15]
Guo et al. (2019)	c.1091–2A>G	Splice-site	Chinese Han	0.178	- Moderate to severe phenotype - Variable age of onset	[15]
Guo et al. (2019)	c.992A>C	Missense	Chinese Han	0.145	- Moderate phenotype - Later onset - Slower progression	[15]
Yang (2021)	c.802–8_810del17insGC (Homozygous)	Insertion-deletion	Chinese	Family study	- Severe phenotype in siblings - Early onset - Rapid progression	[16]
Yang (2021)	c.219T>A (p.F73L) / c.802–8_810del17insGC	Compound heterozygous	Chinese	Family study	- Variable expressivity - Disrupted gene expression - Moderate phenotype	[16]

This table summarizes reported CYP4V2 mutations in Bietti crystalline dystrophy (BCD) patients, primarily from Chinese populations. The data includes mutation types, population frequencies, and associated clinical/experimental findings from various studies (2014–2021). RPE=retinal pigment epithelium. Novel mutations are specifically indicated. Frequencies are reported as percentages where available or described as occurrence patterns in family studies. Clinical findings encompass both phenotypic manifestations and functional impacts on protein structure/function.