Clinical and genetic study of chronic (types II and III) childhood onset spinal muscular atrophy

• Published in: Neuromuscular disorders : NMD 1996-12, Vol.6 (6), p.419-424
• Main Authors: Souchon, Frédérique, Simard, Louise R., Lebrun, Solange, Rochette, Camille, Lambert, Jean, Vanasse, Michel
• Format: Article
• Language: English
• Subjects: Adolescent; Age of Onset; Child; Child, Preschool; Chromosome Deletion; Chronic Disease; chronic spinal muscular atrophy; Demography; Follow-Up Studies; Homozygote; Humans; Infant; molecular genetics; Motor Neurons - physiology; Muscle Weakness - physiopathology; natural history; Nerve Tissue Proteins - genetics; Neuronal Apoptosis-Inhibitory Protein; Retrospective Studies; Spinal Muscular Atrophies of Childhood - genetics; Spinal Muscular Atrophies of Childhood - mortality; Spinal Muscular Atrophies of Childhood - physiopathology; Telomere; Vital Capacity - physiology
• ISSN: 0960-8966; 1873-2364
• DOI: 10.1016/S0960-8966(96)00379-3

We have conducted a retrospective study of 63 patients affected by chronic forms of spinal muscular atrophy (SMA) to better document the natural history of this disease. Thirty-nine patients had type II and 24 type III SMA. These patients had manual muscle testing (MMT) and forced vital capacity (FVC) studies done every six to 12 months over follow up periods ranging from six to 140 months. A decline in FVC was seen in both types of SMA but there was no significant change in MMT in either group. Genetic studies were also done in a subset of 17 families (23 patients) included in this study. Homozygous deletions in the telomeric survival motor neuron (SMN) and the neuronal apoptosis inhibitory protein (NAIP) genes were observed in 100% and 11.8% of the patients tested respectively.