Teaching NeuroImages: Waardenburg syndrome type 2¶

Summary¶

Terminology¶

Original¶

• 5yo M
• c/c
  • Bi congenital sensorineural hearing loss
  • Bi isohypochrmia iridis w/o dystopia canthorum
• Ex
  • MR
    • shortened Post semicircular canal
• Dx
  • Waardenburg synd

A 5-year-old boy presented with bilateral congenital sensorineural hearing loss and bilateral isohypochromia iridis without dystopia canthorum. MRI showed a shortened posterior semicircular canal (figures 1 and 2) compatible with Waardenburg syndrome (WS).

Fig.1¶

Vivid blue eyes Bilateral isohypochromia iridis (vivid blue eyes) in our patient.

Fig.2¶

MRI in Waardenburg syndrome (A–C) Axial T2-weighted imaging (T2WI) shows normal superior semicircular canal (SC) (white arrows), normal lateral SC (yellow arrows), and shortened and thick posterior SC (red arrows). (D) Sagittal T2WI and (E) 3D posterior view show normal superior SC (white arrow) and abnormal posterior SC (red arrow).

Waardenburg synd

type 1	type 2	type 3	type 4
AD	AR	AD	AR
dystopia canthorum(+)	dystopia canthorum(–)	musculoskeleral abnormalities(+)	Hirschesprung(+)

WS is a rare genodermatosis that affects 1:40,000 children and is caused by abnormal migration of melanoblasts from the neuroectoderm. There are 4 types of WS (1 and 3, autosomal dominant; 2 and 4, dominant or recessive). Type 2 differs from type 1 due to the absence of dystopia canthorum. Type 3 is associated with musculoskeletal abnormalities and type 4 with Hirschsprung disease.1,2