Wiedemann-Steiner Syndrome

Main Features

  • Developmental delay/Intellectual disability
  • Hypotonia
  • Distinctive Facial Features

Eye Findings

  • Dysmorphisms
    • Downslanting Palpebral Fissures (74-94%)
    • Vertically narrow (short) palpebral fissures (72-80%)
    • Hypertelorism (77%)
    • Long eyelashes and thick eyebrows
    • Telecanthus and Epicanthus
    • Ptosis (16%)
  • Refractive errors (47%)
  • Strabismus (22%)
  • Amblyopia
  • Lacrimal duct fistuale and stenosis (9%)
  • Retinal anomalies (rare)
  • Microphthalmia (rare)

Other Findings

  • Failure to thrive
  • Short stature
  • Constipation
  • Heart defects
    • PDA, ASD
  • GU
    • renal calyceal dilation, uterine anomalies
  • Immune
    • Hypogammaglobulinemia and recurrent infections
  • Endocrine
    • Growth Hormone deficiency
    • Hypothyroidism
    • premature thelarche
  • Skeletal
    • Vertebral anomalies
    • accelerated skeletal maturation, hypdysplasia brachydactyly, clinodactyly
  • CNS
    • Seizures
    • polymicrogyria, hypoplasia of corpus callosum, Chiari malformation, tethered cord

Etiology

  • Heterozygous (monoallelic) pathologic variant of the KMT2A gene located on chromosome 11q23.
    • KMT2A regulates gene expression during development
  • Prevalence is about 1:25,000 to 40,000.

Resources