- Aplasia of the thymus (HP:0005359): Absence of the thymus. This feature may be appreciated by the lack of a thymic shadow upon radiographic examination. Evidence: TAS. (OMIM:242700)
- Decreased total T cell count (HP:0005403): Abnormal decrease in the absolute number of T cells, commonly characterized as CD3+ lymphocytes, per microliter of blood, compared to a reference range for a given sex and age-group. These may include both TCR alpha/beta and gamma/delta T cells. Evidence: PCS. Frequency: 1/1. (PMID:31566583)
- Reduced delayed hypersensitivity (HP:0002972): Decreased ability to react to a delayed hypersensitivity skin test. Evidence: IEA. (OMIM:242700)
- Recurrent bronchopulmonary infections (HP:0006538): An increased susceptibility to bronchopulmonary infections as manifested by a history of recurrent bronchopulmonary infections. Evidence: IEA. (OMIM:242700)
- Bronchiectasis (HP:0002110): Persistent abnormal dilatation of the bronchi owing to localized and irreversible destruction and widening of the large airways. Evidence: IEA. (OMIM:242700)
- Emphysema (HP:0002097). Evidence: IEA. (OMIM:242700)
- Abnormally low T cell receptor excision circle level (HP:0031545): 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-naïve thymic emigrant T cells. Evidence: PCS. Frequency: 1/1. (PMID:31566583)
- Failure to thrive (HP:0001508): Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm. Evidence: PCS. Frequency: 1/1. (PMID:31566583)
- Decreased total lymphocyte count (HP:0001888): A reduced number of lymphocytes in the blood. Evidence: IEA. (OMIM:242700)
- Eczematoid dermatitis (HP:0000964): Eczema is a form of dermatitis that is characterized by scaly, pruritic, erythematous lesions located on flexural surfaces. Evidence: TAS. (OMIM:242700)
- Autosomal recessive inheritance (HP:0000007): A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in individuals with two pathogenic alleles, either homozygotes (two copies of the same mutant allele) or compound heterozygotes (whereby each copy of a gene has a distinct mutant allele). Evidence: PCS. (PMID:31566583)
- Recurrent viral infections (HP:0004429): Increased susceptibility to viral infections as manifested by recurrent episodes of viral infection. Evidence: PCS. Frequency: 1/1. (PMID:31566583)
- Recurrent pneumonia (HP:0006532): An increased susceptibility to pneumonia as manifested by a history of recurrent episodes of pneumonia. Evidence: IEA. (OMIM:242700)
- Pyoderma (HP:0000999): Any manifestation of a skin disease associated with the production of pus. Evidence: IEA. (OMIM:242700)
- Hepatosplenomegaly (HP:0001433): Simultaneous enlargement of the liver and spleen. Evidence: IEA. (OMIM:242700)
- Neonatal onset (HP:0003623): Onset of signs or symptoms of disease within the first 28 days of life. Evidence: PCS. Frequency: 1/1. (PMID:31566583)
- Chronic diarrhea (HP:0002028): The presence of chronic diarrhea, which is usually taken to mean diarrhea that has persisted for over 4 weeks. Evidence: IEA. (OMIM:242700)
These phenotypes are associated with the disease Nezelof syndrome (OMIM:242700).