Floppy Infant Syndrome: new approach to the study of neonatal hypotonia through the analysis of a rare case of X-Linked Myotubular Myopathy

Abstract

The Floppy Infant Syndrome includes a variety of signs and symptoms: decrease in muscle tone (hypotonia), in muscle power (weakness) and ligamentous laxity and increased range of joint mobility. Strictly speaking, the term “floppy” should be used to describe a form of hypotonia. In our case the clinical and molecular study of a rare form (1:50.000) of X-Linked Myotubular Myopathy (X-Linked MM), with an early onset of peripheral hypotonia, led us to develop a general protocol for the differential diagnosis of neonatal hypotonia.

Keywords

• floppy infant
• weakness
• neonatal hypotonia
• myotubular myopathy
• newborn onset
• central and peripheral hypotonia