Nijmegen breakage syndrome and chronic polyarthritis

A child with polyarthritis and chronic lung disease: a case report of ataxia-telangiectasia

BACKGROUND

Ataxia-telangiectasia (A-T) is a rare autosomal recessive DNA repair disorder, characterized by progressive cerebellar degeneration, telangiectasia, immunodeficiency, recurrent sinopulmonary infections, radiation sensitivity, premature aging and predisposition to cancer. Although the association with autoimmune and chronic inflammatory conditions such as vitiligo, thrombocytopenia and arthritis has occasionally been reported, an onset with articular involvement at presentation is rare.

CASE PRESENTATION

We herein report the case of a 7-year-old Caucasian girl who was admitted to the Rheumatology Department with a history of febrile chough and polyarthritis which led initially to the suspicion of an autoinflammatory disease. She had overt polyarthritis with knees deformities and presented with severe pneumonia. A chest Computed Tomography (CT) scan showed bilateral bronchiectasis, parenchymal consolidation and interstitial lung disease; rheumatoid factor and type I interferon signature resulted negative, therefore excluding COatomer Protein subunit Alpha (COPA) syndrome. A diagnosis of sarcoidosis had been suspected based on histological evidence of granulomatous liver inflammation, but ruled out after detecting normal angiotensin converting enzyme and chitotriosidase blood levels. Based on her past medical history characterized by at least six episodes of pneumonia in the previous 4 years, immunological phenotyping was performed. This showed complete IgA and IgE deficiency with defective antigen-specific antibodies to Pneumococcal, Tetanus toxin and Hemophilus Influenzae B vaccines. Additionally, low numbers of B cells and recent thymic emigrants (RTE) were found (CD4Ra 1.4%), along with a low CD4+/CD8 + T cells ratio (< 1). Finally, based on gait disturbances (wobbly wide-based walking), serum alfa-fetoprotein was dosed, which resulted increased at 276 ng/ml (normal value < 7 ng/ml). A diagnosis of Ataxia-Telangiectasia was made, strengthened by the presence of bulbar telangiectasia, and then confirmed by Whole Exome Sequencing (WES).

CONCLUSIONS

Although rare, A-T should always be ruled out in case of pulmonary bronchiectasis and gait disturbances even in the absence of bulbar or skin telangiectasia. Autoimmune and granulomatous disorders must to be considered as differential diagnosis.

DNA Damage as a Driver for Growth Delay: Chromosome Instability Syndromes with Intrauterine Growth Retardation

DNA is constantly exposed to endogenous and exogenous mutagenic stimuli that are capable of producing diverse lesions. In order to protect the integrity of the genetic material, a wide array of DNA repair systems that can target each specific lesion has evolved. Despite the availability of several repair pathways, a common general program known as the DNA damage response (DDR) is stimulated to promote lesion detection, signaling, and repair in order to maintain genetic integrity. The genes that participate in these pathways are subject to mutation; a loss in their function would result in impaired DNA repair and genomic instability. When the DDR is constitutionally altered, every cell of the organism, starting from development, will show DNA damage and subsequent genomic instability. The cellular response to this is either uncontrolled proliferation and cell cycle deregulation that ensues overgrowth, or apoptosis and senescence that result in tissue hypoplasia. These diverging growth abnormalities can clinically translate as cancer or growth retardation; both features can be found in chromosome instability syndromes (CIS). The analysis of the clinical, cellular, and molecular phenotypes of CIS with intrauterine growth retardation allows inferring that replication alteration is their unifying feature.

Ataxia Telangiectasia and Juvenile Idiopathic Arthritis

We report, to the best of our knowledge, the first case of a child with typical ataxia telangiectasia (A-T) who developed juvenile idiopathic arthritis (JIA). The patient was a 15-year-old boy with A-T who presented with noninfectious polyarthritis. A-T is a rare, autosomal recessive disorder characterized by cerebellar atrophy, oculocutaneous telangiectasia, immunodeficiency, radiosensitivity, and predisposition to cancer. The gene responsible for A-T is the A-T mutated (ATM) gene. Clinical manifestations of the disorder are the result of lacking ATM protein, which is involved in DNA repair, apoptosis, various checkpoints in the cell cycle, gene regulation, translation, initiation, and telomere maintenance. There are a few articles that describe deficiency of the DNA repair enzyme, ATM, in rheumatoid arthritis, but the connection between the absence of ATM protein and JIA has not been presented or studied yet. JIA is a heterogeneous group of diseases characterized by arthritis of unknown origin with onset before the age of 16 years. It is the most common childhood chronic rheumatic disease and causes significant disability. Because immunodeficiency can be part of A-T, infectious arthritis can occur, but chronic autoimmune arthritis in these patients is rare. We report a rare case of a 15-year-old boy with A-T and JIA. This case shows a possible relationship between altered function of ATM protein and the pathogenesis of JIA.