Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS): A family with five affected sibs from Turkey

Abstract Background Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) is one of the more common causes of late-onset progressive ataxia. The genetic background was disclosed by the identification of biallelic pentanucleotide AAGGG repeat expansion in intron 2 of the replication factor complex subunit 1 (RFC1) gene. Case presentation: In this article, the first molecularly confirmed Turkish family with CANVAS with five affected siblings has been described. The family comprised seven siblings born from healthy non-consanguineous parents. CANVAS phenotype was present in five of them. Chronic cough was present in all and it was the first symptom followed by sensory symptoms, oscillopsia and imbalance. Clinical head-impulse test (HIT) was positive in all and video-HIT performed on three patients revealed very low vestibulo-ocular reflex gains bilaterally. Magnetic resonance imaging and nerve conduction studies revealed cerebellar atrophy and sensory neuronopathy. The RP-PCR confirmed the homozygous presence of the AAGGG repeat expansion in the index case and his four affected sibs. Conclusion Genetic screening for CANVAS should be considered in all patients with late-onset ataxia, when sensory disturbances and vestibular involvement has been detected especially in the presence of chronic cough.