Luscan-Lumish syndrome: A case report

Abstract

Background: Luscan-Lumish syndrome (LLS) is a rare genetic congenital anomaly syndrome characterised by neurodevelopmental disorders, including delayed psychomotor development, behavioral difficulties, relative or true macrocephaly and, in individual cases, ocular abnormalities. This paper aims to present the case of a child with ocular abnormalities associated with LLS.

Case summary: A 10-year-old girl born at 40 weeks gestation with features of dysmorphia, neurodevelopmental disorders, genetically confirmed LLS, convergent strabismus and suspected congenital glaucoma. Eye examination, ultrasound, optical coherence tomography (OCT), perimetry and electrophysiological study [pattern visually evoked potentials (VEP)] were performed. Best-corrected distance visual acuity was 0.5 in the right eye (correction -1.0 Dsph, -1.0 Dcyl, axis 180°) and 0.62 in the left eye (correction -2.0 Dsph). Near visual acuity (Snellen Chart) with the above correction was -0.5 D. A cycloplegic refraction test yielded -1.25 Dsph, -1.25 Dcyl, axis 165° in the right eye, and -2.0 Dsph, -0.25 Dcyl, axis 154° in the left eye. Intraocular pressure was 15 mmHg in both eyes. OCT of the maculae showed no abnormalities. In both eyes, the average ganglion cell layer and inner plexiform layer thickness was 73 μm. OCT of the optic nerve disc showed an average retinal nerve fibre layer thickness of 89 μm in the right eye and 81 μm in the left eye, with symmetry of 90%. The rim area was 1.59 mm² and 1.74 mm² in the right and left eye, respectively. The disc area was 2.77 mm² in the right eye and 2.89 mm² in the left. The average cup-to-disc ratio was 0.64 in the right eye and 0.62 in the left eye. Ocular ultrasound depicted single extra echoes inside the vitreous chamber; otherwise, there were no abnormalities. Right and left eyeball lengths were 24.59 mm and 24.51 mm, respectively. Kinetic perimetry revealed no visual field defects, while static testing showed single relative scotomas. The mean defect was 4.7 dB in the right and 2.6 dB in the left eye. The loss variance values were 4.8 and 3.8 dB for the right and left eye, respectively. Pattern VEP test revealed normal values of P100 Latency. Wave amplitude in the right eye was 50% at a visual angle of 1.0° and 30% at 15'. Due to the rarity of LLS, it seems interesting to present the child ophthalmological examination with changes in the electrophysiological examination.

Conclusion: Although eye abnormalities are infrequently described in children with LLS, the patients should undergo eye examinations, especially as they may have central nervous system anomalies that may give rise to visual impairments. Generally, children with genetically determined congenital syndromes should receive regular ophthalmic check-ups for a thorough evaluation of the eyes and prognosis of the development of visual function.

Keywords: Case report; Children; Luscan-Lumish syndrome; Ophthalmology; SETD2.

Figure 1

Child with Luscan-Lumish syndrome.