Inherited retinal dystrophies in a Kuwaiti tribe

ABSTRACT

Purpose

To evaluate the clinical and genetic spectrum of inherited retinal diseases (IRDs) in a Kuwaiti tribe.

Methods

Forty four patients with IRDs from 28 nuclear families from the tribe, were evaluated for presenting symptoms, visual acuity, fundus examination, OCT, microperimetry, full-field (ff), and multifocal electroretinography (mERG) and genotyping.

Results

Seventeen patients were diagnosed with autosomal recessive retinitis pigmentosa (arRP) associated with RP1 c.606C>A with onset of nictalopia in the third decade, myopia, and macular atrophy by the age of 50; eleven with autosomal recessive cone/rod dystrophy or macular dystrophy associated with RP1 c.606C>A (p.Asp202Glu) mutation with color and central vision deterioration in teenage, myopia, paracentral ring scotoma and macular atrophy; eleven were with arRP associated with PDE6B c.992 + 1 G > A mutation with onset around 5 years, myopia, cataract, retained central fixation, and ellipsoid zone and late perimacular atrophy; five—with Leber congenital amaurosis associated with homozygous RPGRIP1 for c.1107delA mutation with extinguished ffERG and electrophysiological phenotype of rod and cone; and one patient—with autosomal recessive rod-cone dystrophy associated with homozygous PDE6B c.992 + 1 G > A, who was homozygous ABCA4 c.5882 G > A and heterozygous EYS; c.2137 + 1 G > A.

Conclusions

This study represents a typical tribe from the Middle East with high rate of consanguinity for many generations that harbors multiple mutated genes associated with IRD. It demonstrates the predominant phenotype and its variability in retinal disorders caused by identical mutations and illustrates the nuances in the clinical presentation and disease progression of patients with pathogenic mutations in more than one gene.

KEYWORDS:

• Retinitis pigmentosa
• rod-cone dystrophy
• leber amaurosis
• Kuwaiti tribe

Acknowledgments

This work was supported by a research grant from the Kuwait Foundation for Advancement of Science.

(Project Code: P115-13MM-01).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Kuwait Foundation for the Advancement of Sciences (KFAS) [Project Code: P115-13MM-01].