Clinical applications of high-throughput genetic diagnosis in inherited retinal dystrophies: Present challenges and future directions

Table 1 List of retinal dystrophy causative and candidate genes identified in 2013-2014 and the strategy of identification

Gene	Retinal phenotype	Methodological approach
ABCD5	Recessive CRD, spastic parapesis, white matter disease	Homozygosity mapping combined with WES[25]
ADAMTS18	arRD early onset	Homozygosity mapping combined with WES[43]
ARLBP2	arRP	Homozygosity mapping combined with WES[44]
BBIP1	arBBS	WES[45]
C12orf65	Recessive optic atrophy, spastic paraplegia and neuropathy	Linkage mapping WES[46,47]
C21orf2	Recessive CRD	Homozygosity mapping combined with WES[25]
CSPP1	Recessive JS	WES[48-50]
DHX38	arRP (early onset with macular coloboma)	Homozygosity mapping combined with candidate gene approach[51]
DTHD1	Recessive LCA, myopathy	Homozygosity mapping combined with WES[25]
EMC1	arRP	Homozygosity mapping combined with WES[25]
GDF6	arRD	Candidate gene sequencing[52]
GPR125	arRP	Homozygosity mapping combined with WES[25]
HK1	adRP, nonspherocytic hemolytic anemia, and neuropathy	Linkage mapping and WES[53]
IFT27	arBBS	Homozygosity mapping combined with candidate gene approach[42]
IMPG1	Dominant MD	Linkage mapping
	Recessive MD	WES and candidate gene sequencing[54-56]
ITM2B	Dominant RD, dementia	WES combined with linkage mapping[57]
KIAA1549	arRP	Homozygosity mapping combined with WES[25]
KIZ	arRP, arCRD	WES[58]
LRIT3	arCSNB	WES[59]
MVK	arRP, recessive mevalonic aciduria	WES[60]
NEK2	arRP	WGS[6]
NR2F1	Dominant optic atrophy, intellectual disability	Deletion mapping
		WES and deletion mapping[61,62]
PCYT1A	arCRD with skeletal disease	WES and targeted candidate gene sequencing[63,64]
POC1B	Recessive CRD	WES[65]
PRPF4	adRP	Targeted capture NGS[41]
RAB28	arCRD	Homozygosity mapping combined with WES[66]
RDH11	arRP	WES[67]
SLC7A14		WES[68]
TUB	arRD with obesity	Homozygosity mapping combined with WES[69,70]
TTLL5	Recessive cone and CRD	WES[71]

ar: Autosomal recessive; ad: Autosomal dominant; CRD: Cone-rod dystrophy; RD: Retinal dystrophy; RP: Retinitis pigmentosa; BBS: Bardet-Biedl syndrome; JS: Joubert syndrome; LCA: Leber congenital amaurosis; MD: Macular dystrophy; CSNB: Congenital stationary night blindness; WES: Whole exome sequencing; WGS: Whole genome sequencing; NGS: Next generation sequencing.