Vitamin metabolism disorders
Gene: TCN1
Unclear if TC1 deficiency is associated with a clinical phenotype and only found 2 families with genetic findings. 1 confirmed chet (2 truncating variants) with severe TC 1 deficiency (depression and anxiety only reported symptoms, had sickle cell trait) & another family with 2 siblings that are presumed homozygous for a truncating variant (no plasma or serum TC 1 levels but no DNA available for genetic testing) which was found heterozygous in multiple first-degree relatives. Unclear if there is a clinical phenotype. Heterozygous individuals displayed mildly low or low-normal TC 1 serum levels. Also, 4 homozygotes were identified in a study of a loss-of-function variant associated with lower vitamin B12 concentration in African Americans but there was limited ability to assess the clinical impact of the recessive disease
Sources: LiteratureCreated: 2 Apr 2024, 10:19 p.m. | Last Modified: 2 Apr 2024, 10:27 p.m.
Panel Version: 0.34
Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal
Phenotypes
transcobalamin I deficiency MONDO:0008659
Publications
Gene: tcn1 has been classified as Amber List (Moderate Evidence).
Gene: tcn1 has been classified as Amber List (Moderate Evidence).
gene: TCN1 was added gene: TCN1 was added to Inherited vitamin B12 or cobalamin deficiency. Sources: Literature Mode of inheritance for gene: TCN1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: TCN1 were set to 19686235 Phenotypes for gene: TCN1 were set to transcobalamin I deficiency MONDO:0008659 Review for gene: TCN1 was set to AMBER