What is STT3B-CDG?

STT3B-CDG is a form of congenital disorders of N-linked glycosylation characterized by intrauterine growth retardation, microcephaly, failure to thrive, developmental delay, intellectual disability, hypotonia, seizures, optic nerve atrophy and respiratory difficulties. Genital abnormalities (micropenis, hypoplastic scrotum, undescended testes) have also been reported. STT3B-CDG is caused by mutations in the gene STT3B (3p24.1).

Other condition names

  • CDG syndrome type Ix
  • CDG-Ix
  • CDG1X
  • Carbohydrate deficient glycoprotein syndrome type Ix
  • Congenital disorder of glycosylation type 1x
  • Congenital disorder of glycosylation type Ix

Inheritance type

Autosomal recessive


  • Worldwide: <1 in 1,000 000

Age of Onset

  • Infancy
  • Neonatal
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