Mikaela Poling
FSRG deGruyter-McKusick Institute of Health Sciences, USA
Title: Freeman-Sheldon syndrome: what one illustrative, severe case tells us about pathophysiology and needed research
Biography
Biography: Mikaela Poling
Abstract
Freeman-Sheldon syndrome (FSS) reported, of which we are aware, recent basic science research on pathophysiology is described and possible ways these findings compliment each-other and resultant implications considered during recent clinical practice guideline development is addressed. While fulfilling Stevenson's 2006 diagnostic criteria, the patient described presented with several previously unreported and rare findings that may serve as 'missing links' in the effort to better appreciate pathophysiology in FSS. Previously unreported findings include: thyroid and cricoid cartilage hypoplasia, a vertical ridge of ossified elevation (right dorsal mid-clavicular line from inferior scapular border to inferior costal margin), left atrophy and right hypertrophy of the latissimus longus and right atrophy and left hypertrophy of the latissimus dorsi muscles, paroxysmal resting tachycardia of typically 110-130 bpm, with a range of 56-215 bpm, without evidence of pathology, severe hyperhidrosis, post-traumatic stress disorder, undersised external auditory canals, and secondary limitation of extra ocular movement. These findings are all consistent with a myopathic aetiology, which was suggested by previous authors and studies. Patient described also experienced subjectively high energy expenditures, estimated to be on the order of 10-25% above normal range. This clinical hypothesis may be at least partially substantiated by recent in vitro muscle fibre studies showing impaired cross-bridging in two patients with one of the more common mutations. Mutations for FSS were previously suggested to impair adenosine triphosphate binding at the embryonic myosin head. Physiological appreciation is critical for FSS outcomes.