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Start free with EleplanSLC39A8-CDG
ORPHA:468699Disease
Also called CDG syndrome type IIn · CDG-IIn · CDG2N · Carbohydrate deficient glycoprotein syndrome type IIn · Congenital disorder of glycosylation type 2n · Congenital disorder of glycosylation type IIn · SLC39A8 deficiency
What it is
A rare congenital disorder of glycosylation characterized by infantile onset of global developmental delay, severe intellectual disability, hypotonia, and variable additional features including short stature, cranial asymmetry, seizures, strabismus, recurrent infections, and osteopenia, among others. Laboratory analysis reveals decreased blood levels of zinc and manganese, as well as an abnormal serum transferrin glycosylation pattern with decreased tetrasialo- and increased asialo-, monosialo-, disialo, and trisialo-transferrin, consistent with a type II congenital disorder of glycosylation. Brain imaging shows cerebellar and/or cerebral atrophy.
Key facts
- Prevalence
- <1 / 1 000 000
- Age of onset
- Neonatal
- Inheritance
- Autosomal recessive
- Classified as
- Disease
Prevalence figures describe populations, not individuals, and are often estimates from a single study. Where the figure is an incidence or a birth prevalence, it says so.
Signs and symptoms
Very common80–99%
6Common30–79%
9Sometimes5–29%
26- Abnormality of the liver
- Astigmatism
- Craniosynostosis
- Cutaneous syndactyly of toes
- Decreased activity of mitochondrial complex II
- Decreased activity of mitochondrial complex IV
- Decreased activity of the pyruvate dehydrogenase complex
- Decreased mitochondrial complex III activity in liver tissue
and 18 more in this range
These ranges are how often a sign appears across everyone diagnosed, not a prediction for one person — most people have some of these and not others. Orphanet also records findings that are specifically absent in this disease; those are in the data but not listed here.
Gene
ICD-10 codes
ICD-10 has no distinct code for most rare diseases, so many are filed under the nearest available one. A shared code identifies the group, not this disease — the ORPHAcode above is what identifies it.
Related health topics
Reached through the ICD-10 categories this disease is filed under, so these describe the broader group rather than this disease specifically.
Cross-references
Orphadata Science: Free access data from Orphanet. © INSERM 1999. Data version 2026-06-23. Available under CC BY 4.0. This is a reference, not medical advice.
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