monomelic amyotrophy O'Sullivan-McLeod syndrome https://www.malacards.org/card/osullivan_mcleod_syndrome UMLS:C2721741 MONDO:0020559 O'Sullivan McLeod syndrome is a benign lower motor neuron disorder and a rare variant of monomelic amyotrophy (MA), characterized by an initial unilateral weakness in the intrinsic hand muscles that eventually spreads to the opposite limb (with an asymmetrical distribution) and that has a very slow progression of muscular atrophy over a 20 year period. Orphanet:99965 MedDRA:10069682 GARD:0019718 MEDGEN:797656