[Infantile spinal atrophy: our experience in the last 25 years]. / Atrofia muscular espinal: revisión de nuestra casuística en los últimos 25 años.

OBJECTIVES: To determine the incidence of spinal muscular atrophy (SMA) in our study population and genetic distribution and epidemiological and clinical characteristics and to analyze the level of care and development. MATERIAL AND METHOD: Retrospective descriptive study of patients treated in our hospital in the past 25 years (from 1987 to early 2013), with a clinical and neurophysiological diagnosis of SMA. RESULTS: A total of 37 patients were found, representing an incidence for our reference population and year of 1 case per 10,000 live births. Males predominated (male/female ratio: 1.6/1). The type of SMA diagnosed more frequently was, type i (26 cases), followed by type ii (9 cases), one case with SMA type iii, and one case of spinal muscular atrophy with respiratory distress type 1 (SMARD1). The most frequent genetic alteration was homozygous deletion of exons 7 and 8 of SMN1 gene in 31 cases, while five patients had atypical genetics. The median survival for type i was 8.0 months and 15.8 years for type ii. CONCLUSIONS: The incidence in our population remains stable at around 1/10.000. Most cases presented with, predominantly male, typical genetics. In approximately 1/10 patients the genetic alteration was different from the classical one to the SMN gene. The prevalence of AME unrelated SMN gene was 1/37. The level of care has increased in line with social and welfare demands in recent years.