A 475 years-old founder effect involving IL12RB1: a highly prevalent mutation conferring Mendelian Susceptibility to Mycobacterial Diseases in European descendants.

Mutations in IFNGR1, IFNGR2, IL12RB1, IL12B, STAT1 and NEMO result in a common clinical phenotype known as Mendelian Susceptibility to Mycobacterial Diseases (MSMD). Interleukin-12 receptor beta1 (IL-12Rbeta1) deficiency is the most common genetic etiology for MSMD. Known mutations affecting IL12RB1 are recessively inherited and are associated with null response to both IL-12 and IL-23. Mutation IL12RB1 1623_1624delinsTT was originally described in 5 families from European origin (2 from Germany; 1 from Cyprus, France and Belgium). Interestingly, this same mutation was found in an unexpectedly high prevalence among IL-12Rbeta1 deficient patients in Argentina: 5-out-of-6 individuals born to unrelated families carried this particular change. To determine whether mutation 1623_1624delinsTT represents a DNA mutational hotspot or a founder effect, 34 polymorphic markers internal or proximal to IL12RB1 were studied in the Argentinean and the Belgian patients. A common haplotype spanning 1.45-3.51Mb was shared by all chromosomes carrying mutation 1623_1624delinsTT, and was not detected on 100 control chromosomes. Applying a modified likelihood-based method the age of the most recent common ancestor carrying mutation 1623_1624delinsTT was estimated in 475 years (95% CI, 175-1275), which is the time when the Spaniards initiated the colonization of the Americas. Mutation 1623_1624delinsTT represents the first founder effect described on IL-12Rbeta1, the most frequently affected gene in MSMD, and affecting patients with European ancestors. The reason(s) behind the persistency of this mutation across multiple generations, its relative high prevalence, and any potential selective advantage are yet to be established.

Inflammatory manifestations in chronic granulomatous disease (CGD).

Chronic granulomatous disease (CGD) is a genetically heterogeneous disease characterized by recurrent life-threatening infections with bacteria and fungi as well as dysregulated inflammatory mechanisms. CGD is caused by defects in the NADPH oxidase, the enzyme complex responsible for generation of superoxide and other reactive oxygen species (ROS) in phagocytic cells. In this review we will focus our attention on those particular inflammatory manifestations associated with CGD, their frequencies and the underlying immunologic mechanisms favoring it occurrence.

Clinical and histopathological features and a unique spectrum of organisms significantly associated with chronic granulomatous disease osteomyelitis during childhood.

Herein, we describe a combination of clinical, microbiologic, and histopathologic findings significantly associated with osteomyelitis in chronic granulomatous disease. When present, these features should raise the suspicion of underlying chronic granulomatous disease. In patients with these findings, anti-infective prophylactic measures aiming to cover highly prevalent microorganisms, as well as aggressive therapeutic measures, should be strongly encouraged.

Penicillium piceum infection: diagnosis and successful treatment in chronic granulomatous disease.

Infections due to Penicillium species other than P.marneffei are rare. We identified a boy with X-linked chronic granulomatous disease (X-CGD) with a pulmonary nodule and adjacent rib osteomyelitis caused by Penicillium piceum. The only sign of infection was an elevated sedimentation rate. P. piceum was isolated by fine needle aspirate and from excised infected tissues. Surgical removal and one year of voriconazole treatment were very well tolerated and led to complete recovery. Microbiological, microscopic and molecular studies support the fungal diagnosis. P. piceum should be considered as a relevant pathogen in immunocompromised patients.

Thirteen years of culture-positive M. bovis-BCG infection in an IL-12Rbeta1 deficient patient: treatment and outcome.

Patients with mutations in the IFNgamma/IL-12 pathway show an exquisite susceptibility to mycobacterial diseases. An IL-12Rbeta1 deficient patient with impaired intestinal absorption suffered from a 13 year culture-positive Mycobacterium bovis-BCG infection with acquired multidrug resistance. A combined parenteral and enteral anti-mycobacterial treatment, including recombinant IFNgamma, helped to clear his infection.

Juvenile rheumatoid arthritis-like polyarthritis in Nijmegen breakage syndrome.

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive disease (8q21) from the family of the genetically determined chromosomal instability syndromes. The disorder is characterized by microcephaly, growth retardation, immunodeficiency, and high incidence of cancer. Several noninflammatory anomalies of the musculoskeletal system have been described in patients with this syndrome. We describe an Argentinian girl with all the clinical, immunological, and cytogenic characteristics described for NBS plus a juvenile rheumatoid arthritis-like syndrome. To our knowledge this is the first report of a patient with the NBS who presented with a symmetric chronic polyarthritis resembling JRA.