Marshall–smith Syndrome

Marshall-Smith Syndrome, discovered in 1971 (Marshall, Graham, Scott, Boner, & Smith), is characterized by unusual accelerated skeletal maturation (usually starting before birth) and symptoms like conspicuous physical characteristics, respiratory difficulties, and mental retardation. Cases described in the literature show a clinical variability regarding related symptoms. For instance, respiratory difficulties are ranging from absent to severe difficulties.

Presentation

The syndrome is a rare clinical disorder.

• Physical
  • Overgrowth
  • Accelerated skeletal maturation
  • Dysmorphic facial features
    • Prominent eyes
    • Bluish sclerae
    • Coarse eyebrows
    • Upturned nose
• Radiologic examination
  • Accelerated osseous maturation
  • Phalangeal abnormalities
  • Tubular thinning of the long bones
  • Skull abnormalities
• Mental
  • Often associated with intellectual disability (of variable degree)

Genotype

The first gene - NFIX - that could cause the syndrome has been identified. This gene is located on the short arm of chromosome 19 (19p13.1).

Diagnosis

• Clinical course
  • Respiratory difficulties (like upper airway obstruction. (Note regarding clinical variability: respiratory difficulties might be absent.)
  • Pneumonia
  • Failure to thrive
  • Psychomotor retardation

Respiratory complications are often cause of death in early infancy.

Differential diagnosis

Marshall–Smith syndrome is not to be confused with:

• Marshall syndrome (aka periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA syndrome, see also: periodic fever syndrome)
• Sotos (like) syndrome (Malan syndrome)
• Weaver-Smith syndrome (WSS)

Terminology

Translated

• English: Marshall–Smith syndrome
• Español: Síndrome de Marshall–Smith
• Français: Le syndrome de Marshall–Smith
• Italiano: Sindrome di Marshall–Smith
• Nederlands: Marshall–Smithsyndroom, syndroom van Marshall–Smith
• Polski: Zespół Marshalla–Smitha, Zespół Marshalla i Smitha
• Русский: Синдром Маршалла–Смита