Peters Anomaly in Twins: A Case Report of a Rare Incident with Novel Comorbidities

Abstract

Introduction: Peters anomaly is a rare developmental malformation involving the anterior segment of the eye, which culminates in amblyopia or congenital blindness. Multiple ocular and/or systemic malformations have been observed with this anomaly, and novel comorbidities continue to be reported. Case Presentation: The probands were monozygotic twin boys (twin I and twin II) born to consanguineous parents at 36 weeks of gestation. Coarse facial features and deep-seated eyes were noted at birth. At 6 months, ophthalmic examination revealed that both twins were unable to blink in response to light, or to fixate and follow a moving object. Both twins had prominent horizontal nystagmus. Slit-lamp examination demonstrated varying degrees of central leukoma (corneal opacity) associated with iridocorneal adhesion, which is characteristic of type I Peters anomaly. No cataractous changes were observed. Normal intraocular pressure and disorganized retina were observed. Pupillary abnormalities included bilaterally underdeveloped pupils and bilateral absence of pupils was noted. Ocular MRI showed bilateral microphthalmia and optic nerve hypoplasia, with a small optic chiasm in both twins. At this age, the diagnosis of Peters anomaly was made. At 16 months of age, both twins developed deep venous thrombosis and purpuric skin lesions. Investigations revealed a hereditary thrombophilia secondary to a homozygous mutation causing protein C deficiency, which is a rare thrombotic condition. Ocular ultrasonography revealed bilateral vitreous hemorrhaging linked to altered coagulation. One twin developed bilateral inguinal hernia and cryptorchidism. Conclusion: The novel concordance of Peters anomaly in these monozygotic twins sharing a mutation in PROC gene provides further evidence that this anomaly has a genetic basis. Hypoplasia of the optic nerves and optic chiasm, along with severe protein C deficiency and bilateral absence of the pupils, are associated comorbidities that have not previously been reported with this anomaly.

Peter’s Anomaly Type 2 with Cataract

“…The cause of Peter's plus syndrome is a beta-1,3-galactosyltransferase gene mutation. Cytomegalovirus infections rarely involve it, which causes many difficulties like microcornea, optic atrophy, coloboma, anophthalmia, Peter's anomaly, and chorioretinitis [6,7]. Systemic abnormality including hydrocephalus, congenital heart defects, and renal dysgenesis was associated with it [8].…”

Ophthalmic manifestations of congenital protein C deficiency: a case report and mini review

“…Total retinal detachment and a left macular hemorrhage Paysse EA [2002] [ 19 ] 1 OU Flat anterior chamber Bilateral retinal detachment, fibrotic hyaloid arteries Sirachainan N et al [2003] [ 20 ] 2 OU Preserving eye function, high myopia, cerebral palsy Park UC et al [2005] [ 21 ] 1 OU Bilateral corneal opacity, microphthalmia, posterior synechia, pupillary membrane, shallow anterior chamber Vitreoretinopathy suggesting, PHPV, intravitreal masses, funnel-shaped retinal detachment with bilateral retinal dysplasia Bilateral leukocoria, no microphthalmos, blind OU de Lemus-Varela ML [2005) [ 22 ] 1 OU Vitreous hemorrhage Douglas AG et al [2010] [ 23 ] 1 OU No red reflex OU Vitreoretinal dysplasia, severe hazy media in one eye and OU PFV Leukocoria OS, bilateral microphthalmia,, deranged VEP, poor vision, nystagmus Wang BZ [2012] [ 24 ] 1 OU Macular hypoplasia with blond retinal background Doll’s eye movements, no fix and follow movement of the eyes, ponto-cerebellar hypoplasia, nystagmus, strabismus, Flat ERG Desai S et.al. [2014] [ 25 ] 1 OU Combined central retinal venous and arterial obstruction Severe Type II protein C deficiency with factor V Leiden mutation, Glaucoma Almarzouki HS et al [2016] [ 26 ] 2 OU Peter’s anomaly Baothman AA et al [2017] [ 27 ] 5 OU Peter’s anomaly, corneal opacity (3/5) Blindness (4/5OU), ocular hemorrhage shortly after birth resulted in visual loss (1/5) Present study 1 OU Left eye shallow anterior chamber, cataract...…”

The 2021 Congress of the International Society for Twin Studies: Twin Research at the Cutting Edge/Twin Research: Maternal Bonding with Twins; Twins with Peters Anomaly; Selective Termination in Dichorionic Twin Pairs; Neuropsychological Function in Twins with Neurofibromatosis/News Reports: World’s Most Premature Survivor — A Twin; Twins Confuse Giants’ Baseball Fans; Malaysian Twins Switched at Birth; ‘Biracial’ Twins

“…The condition was first described in 1906 by Dr Albert Peters. Its rarity and later organization into three classification types has made the search for its etiological factors challenging; however, evidence suggests a role for genetic factors (Almarzouki et al, 2016). Currently, Peters anomaly is considered part of the group of congenital corneal opacities, affecting 3-6 individuals per 100,000 (Medline Plus, 2020).…”