Combined Immunodeficiency
Gene: TCN2

TCN2 (transcobalamin 2)
EnsemblGeneIds (GRCh38): ENSG00000185339
EnsemblGeneIds (GRCh37): ENSG00000185339
OMIM: 613441, Gene2Phenotype
TCN2 is in 11 panels

1 review

Danielle Ariti (University of Melbourne)

Green List (high evidence)

26 pathogenic TCN2 variants have been reported in over 40 individuals; multiple mouse models

Homologous and Compound Heterozygous TCN2 variants (deletions or insertions, nonsense mutations, and point mutations) have been reported; deletions or insertions are the most common, causing frameshifts that result in protein truncation.

Individuals usually present within the first year of life with failure to thrive, diarrhoea, anaemia, pallor and agammaglobulinaemia.
Created: 17 Aug 2021, 1:22 a.m. | Last Modified: 17 Aug 2021, 1:22 a.m.

Panel Version: 0.328

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Transcobalamin II deficiency MIM# 275350; Decreased Ig levels; Megaloblastic anaemia; pancytopaenia; if untreated (B12) for prolonged periods results in intellectual disability; failure to thrive; diarrhoea; hypogammaglobulinaemia; pallor; hypotonia; respiratory infection

Publications

Created: 17 Aug 2021, 1:22 a.m.
Last Modified: 17 Aug 2021, 1:22 a.m.
Panel version: 0.328

Details

Mode of Inheritance

BIALLELIC, autosomal or pseudoautosomal

Sources

Expert Review Green
Melbourne Genomics Health Alliance Immunology Flagship
Victorian Clinical Genetics Services

Phenotypes

Transcobalamin II deficiency MIM# 275350
Decreased Ig levels
Megaloblastic anaemia
pancytopaenia
if untreated (B12) for prolonged periods results in intellectual disability
failure to thrive
diarrhoea
hypogammaglobulinaemia
pallor
hypotonia
respiratory infection

OMIM

613441

Clinvar variants

Variants in TCN2

Penetrance

None

Publications

Panels with this gene