Labrune et al originally reported three cases of children presenting extensive brain calcifications, leukodystrophy and formation of parenchymal cysts on 1996.  On 2016, Jenkinson et al. discovered a mutation on SNORD118 (possibly critical for maturation of ribosomal RNAs).

A 45 years old patient, from São Paulo, Brazil, presented to the emergency department complaining a sub-acute onset headache, nausea and ataxic episodes.  On the physical examination, he had no cognitive, sensitive or motor deficits, but the neurologic examination showed a bilateral dysmetria and gait ataxia. A brain magnetic resonance imaging showed a supratentorial and infratentorial leukoencephalopaty, multiple cerebral and cerebellar cysts and calcifications with one of them compressing the anterior brain stem and the cerebellar parenchyma, which caused cerebral edema and obstructive hydrocephalus. The finding images were compatible with the literature description of adult-onset leukoencephalopathy with intracranial calcifications and cysts (Labrune syndrome).

 A descompressive surgery of the cyst causing the hydrocephalus was made, and the material was sent to histopathological analysis, that showed a degenerative process involving all cerebellar tissue associated with coagulative necrosis, dystrophic microcalcifications and perivascular hialinizations that lead to substitution of extensive neuropil, compatible with the original description of the syndrome. Following the procediment, we made a complet genetic analysis targeting SNORD118, which was negative.

 We described a case with clinical manifestations, imaging and histological patterns that are compatible with Labrune syndrome with negative genetic tests focusing SNORD118. Mutation detection rates approximately 30%, even when not focused on protein coding genes.  We suggest with the case report that next generation sequencing technologies may fail on detecting some mutations, or that Labrunne phenotype may be manifest with other mutations like CTC1, which causes a similar pattern (Coats plus syndrome).