What is ALG1-CDG?

A severe form of congenital disorders of N-linked glycosylation characterized by severe developmental and psychomotor delay, muscular hypotonia, intractable early-onset seizures, and microcephaly. Additional features include altered blood coagulation with a high probability of hemorrhages or thromboses, nephrotic syndrome, ascites, hepatomegaly, cardiomyopathy, ocular manifestations (strabismus, nystagmus), and immunodeficiency. The disease is caused by loss-of-function mutations in the gene ALG1 (16p13.3).

Other condition names

  • CDG syndrome type Ik
  • CDG-Ik
  • CDG1K
  • Carbohydrate deficient glycoprotein syndrome type Ik
  • Congenital disorder of glycosylation type 1k
  • Congenital disorder of glycosylation type Ik
  • Mannosyltransferase 1 deficiency

Inheritance type

Autosomal recessive


  • Worldwide: <1 in 1,000 000

Age of Onset

  • Infancy
  • Neonatal
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