Chromosome: 3p26.2
Gene: TRNT1
Action of gene product: nucleotidyltransferase critical for tRNA processing (catalyzes the addition of the conserved nucleotide triplet CCA to the 3' terminus of tRNA molecules)
Inheritance: autosomal recessive
Features:
(1) congenital sideroblastic anemia
(2) microcystic anemia
(3) B-cell immunodeficiency with lymphopenia and hypogammaglobulinemia
(4) periodic fevers (autoinflammation)
(5) developmental delay
(6) variable mucocutaneous involvement (brittle hair, lichen sclerosus, ichthyosis, erythema, indurated plaques)
(7) failure to thrive
(8) variable vision loss with retinitis pigmentosa
(9) sensorineural hearing loss
(10) variable colitis with diarrhea
(11) variable neurologic disorders (seizures, ataxia, cerebral atrophy)
(12) variable renal abnormalities (aminoaciduria, renal tubular dysfunction, nephrocalcinosis)
(13) variable cardiomyopathy
(14) variable hepatosplenomegaly
Targeted therapy with anti-TNF agents may prevent some of the more severe manifestations.
