A wolf in sheep’s clothing

Abstract

A 28 year-old Caucasian woman was found to have reduced visual acuity during routine optician checks and was referred to ophthalmology and then neurology. Examination revealed acuities of 6/12 in both eyes, pale optic discs and reduced colour perception. MRI brain did not show any lesions. Routine bloods were normal as were serum ACE, B1, B12, folate, HIV, syphilis, Lyme serology, AQP4-IgG and MOG-IgG. Leber’s and AD optic atrophy screens were negative. CSF protein was 0.41, WBC 7 (100% lymphocytes), elevated IgG Index 1.4 (normal<0.8),OCBs in serum and CSF with a single additional band raising the possibility of inflammatory optic neuritis. There was apparent stabilisation on empiric steroids which was then converted to steroid sparing immunosuppressants. However, as vision declined, whole mitochondrial genome sequencing and the clinical Exome Optic Atrophy Panel revealed compound heterozygous WFS1 mutations (c.605A>G p. (Glu2020Gly); c.874C>T p.(Pro292Ser) leading to diagnosis of‘Wolfram’Syndrome or DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy, deafness) with an isolated optic atrophy phenotype. This case is unusual given the late age of presentation, lack of classical associ- ated features, suggestion of CSF inflammation and apparent steroid responsiveness. It also highlights the importance of expanded genetic testing in atypical optic atrophy cases.emily.gibbons@doctors.org.uk