- 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: TAS. (OMIM:601705)
- Alopecia (HP:0001596): A noncongenital process of hair loss, which may progress to partial or complete baldness. Evidence: TAS. Onset: Congenital onset (HP:0003577). (OMIM:601705)
- Ridged nail (HP:0001807): Longitudinal, linear prominences in the nail plate. Evidence: TAS. (OMIM:601705)
- Severe T-cell immunodeficiency (HP:0005352): A primary immune deficiency that is characterized by defects or deficiencies of T-lymphocytes that causes specific susceptibility to intracellular micro-organisms. Evidence: TAS. (OMIM:601705)
- 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: TAS. (OMIM:601705)
- Nail pits (HP:0001803): Small (typically about 1 mm or less in size) depressions on the dorsal nail surface. Evidence: TAS. (OMIM:601705)
- 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: IEA. (OMIM:601705)
- Decreased total CD4+ T cell proportion (HP:0032218): Abnormal decrease of helper CD3+CD4+ T cells, measured as percentage of total CD3+ T cells in the blood, compared to a reference range for a given sex and age-group. These are usually measured within the TCR alpha/beta positive population. Evidence: TAS. (OMIM:601705)
These phenotypes are associated with the disease T-cell immunodeficiency, congenital alopecia, and nail dystrophy (OMIM:601705).