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Abstract Background Doyne honeycomb retinal dystrophy (DHRD)/malattia leventinese (ML) is an autosomal dominant, progressive retinal disorder characterized by massive central retinal drusen often partly coalescent forming a characteristic honeycomb‐like pattern. Debut of vision loss often occurs in early to mid‐adulthood, and the degree varies. A single variant in EFEMP1: c.1033C>T (R345W) has been identified as the cause in all cases. Methods Following DNA isolation, exome sequencing was performed in seven genes associated with flecked retina. Direct sequencing was used for variant verification. Results We report the first Scandinavian case of molecular genetically verified DHRD/ML: a 57‐year‐old woman debuting with vision loss and metamorphopsia. On both eyes, ophthalmological findings included massive hard drusen in the macular region and nasal to the optic disc as well as macular hyperpigmentation. Secondary choroidal neovascularizations were identified on both eyes, and anti‐vascular endothelial growth factor was administered, without effect. Conclusion Molecular genetic investigation revealed heterozygosity for the known pathogenic missense variant in EFEMP1: c.1033C>T (R345W) previously reported in relation to DHRD/ML. Family history revealed no other cases of similar visual impairment suggesting a de novo mutation. Furthermore, there was no correlation between the unique DHRD/ML haplotypes reported in the literature and our patient.

Abstract Background CABP2‐related non‐syndromic hearing loss have only been reported in a few families worldwide (Iran, Turkey, Pakistan and Italy). The hearing loss was in these cases described as prelingual, symmetrical, and moderate to severe. Methods Following DNA isolation, exome sequencing was performed in 123 genes related to non‐syndromic hearing loss. Variant verification and carrier testing were performed by direct sequencing. Results We report the first Northern European individual with CABP2‐related hearing loss: an 8‐year‐old Danish Caucasian boy with non‐syndromic, prelingual, and sensorineural hearing loss, who is homozygous for the splice site variant CABP2: c. 637+1G>T previously found in three Iranian families and in one Pakistani family. Both parents are of Danish Caucasian origin with no known history of consanguinity. This is in contrast to the four reported Middle Eastern families, who all were consanguineous. However, loss of heterozygosity in a 3.2 Mb area on chromosome 11 including CABP2 was observed, suggesting a common parental ancestor. Conclusion We report the first case of CABP2‐related autosomal recessive hearing loss in Northern Europe. The index is of Danish Caucasian origin and found to be homozygous for the splice site variant c.637+1G>T.