Distal spinal muscular atrophy (DSMA), also known as distal hereditary motor neuronopathy (dHMN or HMN), is characterized by distal muscle weakness and wasting without significant sensory involvement.
Viollet et al. (2002) reported a large inbred family afftected with chronic distal spinal muscular atrophy. Five children in this family were affected. Haplotype anaysis on 17 members of this family pointed to a causative locus to chromosome 11q13 between D11S1889 and D11S1321. Although this region included IGHMBP2, no mutations were found in this gene. this promted the authiors to suggest that the condition in this family was distinct from SMARD1.