Abstracts

Objective: Molecularly characterize a series of hereditary ataxias evaluated in a center of Buenos Aires.Background: Hereditary ataxias comprise a diverse group of neurodegenerative disorders.Clinical phenotypes vary from predominantly cerebellar syndromes to sensorimotor neuropathy, ophthalmological disturbances, involuntary movements, seizures, cognitive dysfunction, skeletal abnormalities and cutaneous disorders, among others.The new genetic diagnostic techniques allowed a huge knowledge expansion of hereditary ataxias, with a growing number of new variants as causatives.Classically, a regional distribution of some of them is described.There is a lack of a national registry in Argentina, with only case descriptions published in the literature.Methods: Data was obtained from the medical records of 50 patients with a diagnosis of ataxia.The positive molecular diagnosis was prioritized in order to typify the demographic and clinical characteristics and identify the most prevalent variants in our cohort.Results: The sample included 25 men and 25 women.The average age of onset was 52.5 years.The average time of disease evolution was 3.18 years.38% (n = 19) had a positive family history.22 patients agreed to the molecular study corresponding to the following diagnoses: SCA3 (n = 9, corresponding to 4 families), SCA1 (n = 1), SCA2 (n = 4), SCA10 (n = 1), Friedreich's ataxia (n = 4), Episodic Ataxia type 1 (n = 1); Stub 1 (n = 1), FMR-1 (n = 1).The predominant symptom at onset was gait instability and falls.A proportion of cases had another neurological signs (5.5%) in which pyramidalism and lower limb polyneuropathy (MMII) were the most frequent ones.It is important to highlight the presence of Anti-GAD antibodies in one of the patients with SCA2 (+), with a positive response to the administration of intravenous immunoglobulins.By last, in one SCA3 families the presence of triplet expansion for Kennedy disease was identified in one of its members.Conclusions: This case series demonstrates that SCA3 is the most prevalent variant in our center.On the other hand, although exceptional, we mention the coexistence of genetic and immunomediated causes, in addition to the coexistence of two entities related to triplet expansions in the same family.