Purpose
X-linked Reticulate Pigmentary Disorder is a rare genetic disorder described in only 4 families to date. Initially described in a Canadian family, male members were noted to have diffuse reticulate pigmentation of skin and corneal dyskeratosis with significant photophobia. Other systemic manifestations include hypohidrosis, upswept frontal hairlines, flared eyebrows, and recurrent pulmonary, genitourinary and gastrointestinal abnormalities. We assessed a Texan family comprising two brothers affected with this condition previously linked to a 4.9 Mb region of chr X. Our purpose was to define the ocular phenotype, delineate course of this disease, and document response to treatment.
Methods
Members of the Texas family were enlisted in the study; subjects had a slit lamp examination and exam under anesthesia given significant photophobia. Skin and urethral mucosal biopsies were performed on subject 1.
Results
Subjects were the only affected members of their family with corneal and systemic manifestations. An affected sister (carrier of trait) only had isolated cutaneous findings. Photophobia onset was noted at age 2 and of corneal opacities around age 5. Subject 1 (Figure 1) underwent 10 superficial keratectomies with excimer phototherapeutic keratectomy over a 6-year period. Exam under anesthesia revealed bilateral elevated grey corneal opacities with mild anterior and mid-stromal vessels in both subjects. Subject 1 also had patchy anterior stromal scarring and secondary lipid deposition notably absent in Subject 2 (Figure 2), who has had no surgical treatments to date. The iris, lens, and dilated fundus examinations with indirect ophthalmoscopy were otherwise unremarkable. Slit lamp exam revealed a normal tear lake and Schirmer’s testing at 5 minutes with anesthesia was elevated indicative of reflex tearing. Tissue biopsy results of urethral mucosa revealed granulation tissue with squamous metaplasia, hyperkeratosis, and parakeratosis. Punch biopsy specimen of skin demonstrated basket weave stratum corneum and acanthotic epidermis with necrotic keratinocytes.
Conclusions
Our study revealed that corneal dyskeratosis in X-linked reticulate pigmentary disorder results in significant vision disability and photophobia secondary to elevated anterior corneal opacities. Phototherapeutic keratectomy was associated with recurrence of lesions within a few months and worsening of stromal scarring.
Keywords: 479 cornea: clinical science •
494 degenerations/dystrophies •
539 genetics