Phenotypes associated with the disease T-cell lymphopenia, infantile, with or without nail dystrophy, autosomal dominant (OMIM:618806):
- 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: 21/21. Onset: Congenital onset (HP:0003577). (PMID:31447097)
- Atopic dermatitis (HP:0001047): Atopic dermatitis (AD) or atopic eczema is an itchy, inflammatory skin condition with a predilection for the skin flexures. It is characterized by poorly defined erythema with edema, vesicles, and weeping in the acute stage and skin thickening (lichenification) in the chronic stage. Evidence: PCS. Frequency: 3/25. Onset: Infantile onset (HP:0003593). (PMID:31447097)
- Recurrent upper respiratory tract infections (HP:0002788): An increased susceptibility to upper respiratory tract infections as manifested by a history of recurrent upper respiratory tract infections (running ears - otitis, sinusitis, pharyngitis, tonsillitis). Evidence: PCS. Onset: Infantile onset (HP:0003593). (PMID:31447097)
- Pneumonia (HP:0002090): Inflammation of any part of the lung parenchyma. Evidence: PCS. Frequency: 5/25. Onset: Infantile onset (HP:0003593). (PMID:31447097)
- Nail dystrophy (HP:0008404): Onychodystrophy (nail dystrophy) refers to nail changes apart from changes of the color (nail dyschromia) and involves partial or complete disruption of the various keratinous layers of the nail plate. Evidence: PCS. Frequency: 10/25. Onset: Infantile onset (HP:0003593). (PMID:31447097)
- 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: 21/21. Onset: Congenital onset (HP:0003577). (PMID:31447097)
- Autosomal dominant inheritance (HP:0000006): 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 heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele. Evidence: PCS. (PMID:31447097)