Bilateral Proliferative Retinopathy Associated With Hoyeraal-Hreidarsson Syndrome, a Severe Form of Dyskeratosis Congenita

Ocular findings and genomics of X-linked recessive disorders: A review

Advent of new sequencing technologies and modern diagnostic procedures has opened the door for a deeper understanding of disorders about which little was known previously. Discovery of novel genes, new genetic variants in previously known genes and better techniques of functional validation has immensely contributed to unraveling the molecular basis of genetic disorders. Availability of knockout animal models like the zebrafish and gene editing tools like CRISPR-Cas9 has elucidated the function of many new genes and helped us to better understand the functional consequences of various gene defects. This has also led to better diagnosis and therapeutic interventions. In this context, a good body of research work has been done on X-linked recessive disorders with ocular findings. This review will focus on ocular and genetic findings of these rare disorders. To our knowledge, this is the first comprehensive review encompassing ocular and genomic spectrum of X-linked recessive disorders.

Ocular manifestations of skin diseases with pathological keratinization abnormalities

Keratinization means cytodifferentiation of keratinocytes turning into corneocytes in the stratum corneum. Disorders of keratinization (hyperkeratosis, parakeratosis and dyskeratosis) are causing many dermatological diseases, including various types of ichthyoses, pachyonychia congenita, pityriasis rubra pilaris, all subtypes of psoriasis, pityriasis lichenoides, dyskeratosis congenita, leukoplakia and keratosis follicularis, which apart from skin lesions may affect the eye’s adnexae causing ectropion, entropion, blepharitis, madarosis, and trichiasis, the ocular surface causing keratitis, conjunctivitis, corneal ulceration and episcleritis, which in turn cause uveitis and various fundoscopic changes (proliferative retinopathy, retinal vasculopathy, macular oedema and birdshot chorioretinopathy). Knowledge of ocular symtoms associated with pathological keratinization is crucial, preventing sight-threatening complications such as corneal perforation, lagophthalmus, phthisis bulbi, retinal neovascularization, retinal vasculopathy and optic nerve atrophy. This review encourages dermatologists to monitor patients for ocular symptoms and encourage ophthalmologists to monitor patients for dermatological symptoms.

Revesz syndrome revisited

Background

Revesz syndrome (RS) is an extremely rare variant of dyskeratosis congenita (DKC) with only anecdotal reports in the literature.

Methods

To further characterize the typical features and natural course of the disease, we screened the English literature and summarized the clinical and epidemiological features of previously published RS cases. In addition, we herein describe the first recorded patient in central Europe.

Results

The literature review included 18 children. Clinical features are summarized, indicating a low prevalence of the classical DKC triad. All patients experienced early bone marrow failure, in most cases within the second year of life (median age 1.5 years; 95% CI 1.4–1.6). Retinopathy occurred typically between 6 and 18 months of age (median age 1.1 years; 95% CI 0.7–1.5). The incidence of seizures was low and was present in an estimated 20% of patients. The onset of seizures was exclusively during early childhood. The Kaplan–Meier estimate of survival was dismal (median survival 6.5 years; 95% CI 3.6–9.4), and none of the patients survived beyond the age of 12 years. Stem cell transplantation (SCT) was performed in eight children, and after a median of 22 months from SCT four of these patients were alive at the last follow up visit.

Conclusion

RS is a severe variant of DKC with early bone marrow failure and retinopathy in all patients. Survival is dismal, but stem cell transplantation may be performed successfully and might improve prognosis in the future.

Retinal manifestations of the neurocutaneous disorders

PURPOSE OF REVIEW

The neurocutaneous disorders are a genetically and phenotypically diverse group of congenital syndromes characterized by cutaneous, ocular, and central nervous system manifestations. This review provides an overview of the clinical features and retinal findings in selected neurocutaneous disorders.

RECENT FINDINGS

Advances in genetics and diagnostic retinal and neuroimaging allow for the recognition of retinal features of common neurocutaneous syndromes and for improved characterization of rarer entities based on previously underdiagnosed or unrecognized retinal findings.

SUMMARY

Better characterization of the neurocutaneous disorders allows for earlier recognition and the potential for expeditious vision-saving and life-saving treatment.

Late exudative retinopathy after laser treatment for retinopathy of prematurity in a child with dyskeratosis congenita

Exudative retinopathy may be a manifestation of a variety of isolated ocular or systemic diseases in children. We report the case of a teenager with dyskeratosis congenita who developed a unilateral late exudative retinopathy after having previous laser treatment for threshold retinopathy of prematurity as an infant.