Human Phenotype Ontology 
Grandparent Node:
expandAbnormal lymphocyte count (HP:0040088)help
Grandparent Node:
expandAbnormal T cell morphology (HP:0002843)help
Parent Node:
expandAbnormal T cell count (HP:0011839)help
..Starting node
..expandAbnormally low T cell receptor excision circle level (HP:0031545)help
Term ID: 31545
Name: Abnormally low T cell receptor excision circle level
Synonym:
Definition: Reduced level of T cell receptor excision circle (TRECs) as measured by the TREC assay. Late in maturation, 70% of thymocytes that will ultimately express alpha/beta-T cell receptors form a circular DNA TREC from the excised TCRdelta gene that lies within the TCRalpha genetic locus. The circles are stable but do not increase following cell division and, therefore, become diluted as T cells proliferate. A quantitative polymerase chain reaction (PCR) reaction across the joint of the circular DNA provides the TREC copy number, a marker of newly-formed, antigenically-naC/ve thymic emigrant T cells.
Comments:
Reference: HP:0031545
Genes and Diseases:
 
       Child Nodes:

 Sister Nodes: 
..expandAbnormal T cell subset distribution (HP:0025540) help
..expandIncreased T cell count (HP:0100828) help
InputHPO IDHPO termDistanceGeneGene id entrezHGNC IDDiseaseIdDiseaseNameFrequencyOnsetHGMD variantsClinVar variants
 
HPO disease - gene - phenotype typical associations:
 
HPO disease - gene - phenotype less frequent non-typical associations:
HP:0031545HP:0031545Abnormally low T cell receptor excision circle level0DCLRE1C CL E G H6442117642OMIM:602450Severe combined immunodeficiency with sensitivity to ionizing radiation94
HP:0031545HP:0031545Abnormally low T cell receptor excision circle level0FOXN1 CL E G H845612765OMIM:618806T-CELL LYMPHOPENIA, INFANTILE, WITH OR WITHOUT NAIL DYSTROPHY, AUTOSOMAL DOMINANT; TLIND54
HP:0031545HP:0031545Abnormally low T cell receptor excision circle level0IL2RG CL E G H35616010ORPHA:276T-B+ severe combined immunodeficiency due to gamma chain deficiencyHP:0040282 - Frequent48
HP:0031545HP:0031545Abnormally low T cell receptor excision circle level0LCP2 CL E G H39376529OMIM:619374IMMUNODEFICIENCY 81; IMD81
HP:0031545HP:0031545Abnormally low T cell receptor excision circle level0RAC2 CL E G H58809802OMIM:618986IMMUNODEFICIENCY 73B WITH DEFECTIVE NEUTROPHIL CHEMOTAXIS AND LYMPHOPENIA; IMD73B9
HP:0031545HP:0031545Abnormally low T cell receptor excision circle level0RAC2 CL E G H58809802OMIM:618987IMMUNODEFICIENCY 73C WITH DEFECTIVE NEUTROPHIL CHEMOTAXIS AND HYPOGAMMAGLOBULINEMIA; IMD73C9
HP:0031545HP:0031545Abnormally low T cell receptor excision circle level0RAC2 CL E G H58809802OMIM:608203NEUTROPHIL IMMUNODEFICIENCY SYNDROME9
HP:0031545HP:0031545Abnormally low T cell receptor excision circle level0RPA1 CL E G H611710289OMIM:619767PULMONARY FIBROSIS AND/OR BONE MARROW FAILURE, TELOMERE-RELATED, 6; PFBMFT6


Genes (6) :DCLRE1C FOXN1 IL2RG LCP2 RAC2 RPA1

Diseases (8) :OMIM:602450 OMIM:618806 ORPHA:276 OMIM:619374 OMIM:618986 OMIM:618987 OMIM:608203 OMIM:619767
 

Human Phenotype Ontology(HPO) is developed by the Human Phenotype Ontology Consortium. The version used here is December 15 2022 release.