Probing the functional consequence and clinical relevance of CD320 p.E88del, a variant in the transcobalamin receptor gene.
Am J Med Genet A
; 188(4): 1124-1141, 2022 04.
Article
em En
| MEDLINE
| ID: mdl-35107211
ABSTRACT
The biological and clinical significance of the p.E88del variant in the transcobalamin receptor, CD320, is unknown. This allele is annotated in ClinVar as likely benign, pathogenic, and of uncertain significance. To determine functional consequence and clinical relevance of this allele, we employed cell culture and genetic association studies. Fibroblasts from 16 CD320 p.E88del homozygotes exhibited reduced binding and uptake of cobalamin. Complete ascertainment of newborns with transiently elevated C3 (propionylcarnitine) in New York State demonstrated that homozygosity for CD320 p.E88del was over-represented (7/348, p < 6 × 10-5 ). Using population data, we estimate that ~85% of the p.E88del homozygotes born in the same period did not have elevated C3, suggesting that cobalamin metabolism in the majority of these infants with this genotype is unaffected. Clinical follow-up of 4/9 homozygous individuals uncovered neuropsychological findings, mostly in speech and language development. None of these nine individuals exhibited perturbation of cobalamin metabolism beyond the newborn stage even during periods of acute illness. Newborns homozygous for this allele in the absence of other factors are at low risk of requiring clinical intervention, although more studies are required to clarify the natural history of various CD320 variants across patient populations.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transcobalaminas
/
Receptores de Superfície Celular
Tipo de estudo:
Prognostic_studies
Limite:
Humans
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Infant
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Newborn
Idioma:
En
Revista:
Am J Med Genet A
Assunto da revista:
GENETICA MEDICA
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Estados Unidos